What are some of the cognitive changes that happen during adolescense and early adulthood?

chapter 11 Physical and Cognitive Development in Adolescence


The dramatic physical and cognitive changes of adolescence make it both an exhilarating and apprehensive period of development. Although their bodies are full-grown and sexually mature, these exuberant teenagers have many skills to acquire and hurdles to surmount before they are ready for full assumption of adult roles.

chapter outline


·   Conceptions of Adolescence

·   The Biological Perspective

·   The Social Perspective

·   A Balanced Point of View

·   Puberty: The Physical Transition to Adulthood

·   Hormonal Changes

·   Body Growth

·   Motor Development and Physical Activity

·   Sexual Maturation

·   Individual Differences in Pubertal Growth

·   Brain Development

·   Changing States of Arousal

·   The Psychological Impact of Pubertal Events

·   Reactions to Pubertal Changes

·   Pubertal Change, Emotion, and Social Behavior

·   Pubertal Timing

·   Health Issues

·   Nutritional Needs

·   Eating Disorders

·   Sexuality

·   Sexually Transmitted Diseases

·   Adolescent Pregnancy and Parenthood

·   Substance Use and Abuse

· ■  SOCIAL ISSUES: HEALTH  Lesbian, Gay, and Bisexual Youths: Coming Out to Oneself and Others


·   Piaget’s Theory: The Formal Operational Stage

·   Hypothetico-Deductive Reasoning

·   Propositional Thought

·   Follow-Up Research on Formal Operational Thought

·   An Information-Processing View of Adolescent Cognitive Development

·   Scientific Reasoning: Coordinating Theory with Evidence

·   How Scientific Reasoning Develops

·   Consequences of Adolescent Cognitive Changes

·   Self-Consciousness and Self-Focusing

·   Idealism and Criticism

·   Decision Making

·   Sex Differences in Mental Abilities

·   Verbal Abilities

·   Mathematical Abilities

· ■  BIOLOGY AND ENVIRONMENT  Sex Differences in Spatial Abilities

·   Learning in School

·   School Transitions

·   Academic Achievement

·   Dropping Out

· ■  SOCIAL ISSUES: EDUCATION  Media Multitasking Disrupts Attention and Learning


On Sabrina’s eleventh birthday, her friend Joyce gave her a surprise party, but Sabrina seemed somber during the celebration. Although Sabrina and Joyce had been close friends since third grade, their relationship was faltering. Sabrina was a head taller and some 20 pounds heavier than most girls in her sixth-grade class. Her breasts were well-developed, her hips and thighs had broadened, and she had begun to menstruate. In contrast, Joyce still had the short, lean, flat-chested body of a school-age child.

Ducking into the bathroom while the other girls put candles on the cake, Sabrina frowned at her image in the mirror. “I’m so big and heavy,” she whispered. At church youth group on Sunday evenings, Sabrina broke away from Joyce and joined the eighth-grade girls. Around them, she didn’t feel so large and awkward.

Once a month, parents gathered at Sabrina’s and Joyce’s school to discuss child-rearing concerns. Sabrina’s parents, Franca and Antonio, attended whenever they could. “How you know they are becoming teenagers is this,” volunteered Antonio. “The bedroom door is closed, and they want to be alone. Also, they contradict and disagree. I tell Sabrina, ‘You have to go to Aunt Gina’s on Saturday for dinner with the family.’ The next thing I know, she’s arguing with me.”

Sabrina has entered  adolescence , the transition between childhood and adulthood. In industrialized societies, the skills young people must master are so complex and the choices confronting them so diverse that adolescence is greatly extended. But around the world, the basic tasks of this period are much the same. Sabrina must accept her full-grown body, acquire adult ways of thinking, attain greater independence from her family, develop more mature ways of relating to peers of both sexes, and begin to construct an identity—a secure sense of who she is in terms of sexual, vocational, moral, ethnic, religious, and other life values and goals.

The beginning of adolescence is marked by  puberty , a flood of biological events leading to an adult-sized body and sexual maturity. As Sabrina’s reactions suggest, entry into adolescence can be an especially trying time for some young people. In this chapter, we trace the events of puberty and take up a variety of health concerns—physical exercise, nutrition, sexual activity, substance abuse, and other challenges that many teenagers encounter on the path to maturity.


Adolescence also brings with it vastly expanded powers of reasoning. Teenagers can grasp complex scientific and mathematical principles, grapple with social and political issues, and delve deeply into the meaning of a poem or story. The second part of this chapter traces these extraordinary changes from both Piaget’s and the information-processing perspective. Next, we examine sex differences in mental abilities. Finally, we turn to the main setting in which adolescent thought takes shape: the school.


image4 Conceptions of Adolescence

Why is Sabrina self-conscious, argumentative, and in retreat from family activities? Historically, theorists explained the impact of puberty on psychological development by resorting to extremes—either a biological or a social explanation. Today, researchers realize that biological and social forces jointly determine adolescent psychological change.

The Biological Perspective

TAKE A MOMENT…  Ask several parents of young children what they expect their sons and daughters to be like as teenagers. You will probably get answers like these: “Rebellious and irresponsible,” “Full of rages and tempers.” This widespread storm-and-stress view dates back to major early-twentieth-century theorists. The most influential, G. Stanley Hall, based his ideas on Darwin’s theory of evolution. Hall ( 1904 ) described adolescence as a period so turbulent that it resembled the era in which humans evolved from savages into civilized beings. Similarly, in Freud’s psychosexual theory, sexual impulses reawaken in the genital stage, triggering psychological conflict and volatile behavior. As adolescents find intimate partners, inner forces gradually achieve a new, mature harmony, and the stage concludes with marriage, birth, and child rearing. In this way, young people fulfill their biological destiny: sexual reproduction and survival of the species.

The Social Perspective

Contemporary research suggests that the storm-and-stress notion of adolescence is exaggerated. Certain problems, such as eating disorders, depression, suicide, and lawbreaking, do occur more often than earlier (Farrington,  2009 ; Graber,  2004 ). But the overall rate of serious psychological disturbance rises only slightly from childhood to adolescence, reaching 15 to 20 percent (Merikangas et al.,  2010 ). Though much greater than the adulthood rate (about 6 percent), emotional turbulence is not a routine feature of the teenage years.

The first researcher to point out the wide variability in adolescent adjustment was anthropologist Margaret Mead ( 1928 ). She returned from the Pacific islands of Samoa with a startling conclusion: Because of the culture’s relaxed social relationships and openness toward sexuality, adolescence “is perhaps the pleasantest time the Samoan girl (or boy) will ever know” ( p. 308 ). Mead offered an alternative view in which the social environment is entirely responsible for the range of teenage experiences, from erratic and agitated to calm and stress-free. Later researchers found that Samoan adolescence was not as untroubled as Mead had assumed (Freeman,  1983 ). Still, she showed that to understand adolescent development, researchers must pay greater attention to social and cultural influences.

A Balanced Point of View

Today we know that biological, psychological, and social forces combine to influence adolescent development (Susman & Dorn,  2009 ). Biological changes are universal—found in all primates and all cultures. These internal stresses and the social expectations accompanying them—that the young person give up childish ways, develop new interpersonal relationships, and take on greater responsibility—are likely to prompt moments of uncertainty, self-doubt, and disappointment in all teenagers. Adolescents’ prior and current experiences affect their success in surmounting these challenges.

At the same time, the length of adolescence and its demands and pressures vary substantially among cultures. Most tribal and village societies have only a brief intervening phase between childhood and full assumption of adult roles (Weisfield,  1997 ). In industrialized nations, young people face prolonged dependence on parents and postponement of sexual gratification while they prepare for a productive work life. As a result, adolescence is greatly extended—so much so that researchers commonly divide it into three phases:

· 1. Early adolescence (11–12 to 14 years): This is a period of rapid pubertal change.

· 2. Middle adolescence (14 to 16 years): Pubertal changes are now nearly complete.

· 3. Late adolescence (16 to 18 years): The young person achieves full adult appearance and anticipates assumption of adult roles.

The more the social environment supports young people in achieving adult responsibilities, the better they adjust. For all the biological tensions and uncertainties about the future that teenagers feel, most negotiate this period successfully. With this in mind, let’s look closely at puberty, the dawning of adolescent development.

image5 Puberty: The Physical Transition to Adulthood

The changes of puberty are dramatic: Within a few years, the body of the school-age child is transformed into that of a full-grown adult. Genetically influenced hormonal processes regulate pubertal growth. Girls, who have been advanced in physical maturity since the prenatal period, reach puberty, on average, two years earlier than boys.

Hormonal Changes

The complex hormonal changes that underlie puberty occur gradually and are under way by age 8 or 9. Secretions of growth hormone (GH) and thyroxine (see  Chapter 7  page 219 ) increase, leading to tremendous gains in body size and to attainment of skeletal maturity.

Sexual maturation is controlled by the sex hormones. Although we think of estrogens as female hormones and androgens as male hormones, both types are present in each sex but in different amounts. The boy’s testes release large quantities of the androgen testosterone, which leads to muscle growth, body and facial hair, and other male sex characteristics. Androgens (especially testosterone for boys) exert a GH-enhancing effect, contributing greatly to gains in body size. Because the testes secrete small amounts of estrogen as well, 50 percent of boys experience temporary breast enlargement. In both sexes, estrogens also increase GH secretion, adding to the growth spurt and, in combination with androgens, stimulating gains in bone density, which continue into early adulthood (Cooper, Sayer, & Dennison,  2006 ; Styne,  2003 ).

Estrogens released by girls’ ovaries cause the breasts, uterus, and vagina to mature, the body to take on feminine proportions, and fat to accumulate. Estrogens also contribute to regulation of the menstrual cycle. Adrenal androgens, released from the adrenal glands on top of each kidney, influence girls’ height spurt and stimulate growth of underarm and pubic hair. They have little impact on boys, whose physical characteristics are influenced mainly by androgen and estrogen secretions from the testes.

As you can see, pubertal changes are of two broad types: (1) overall body growth and (2) maturation of sexual characteristics. We have seen that the hormones responsible for sexual maturity also affect body growth, making puberty the time of greatest sexual differentiation since prenatal life.

Body Growth

The first outward sign of puberty is the rapid gain in height and weight known as the  growth spurt . On average, it is under way for North American girls shortly after age 10, for boys around age 12½. Because estrogens trigger and then restrain GH secretion more readily than androgens, the typical girl is taller and heavier during early adolescence (Archibald, Graber, & Brooks-Gunn,  2006 ; Bogin,  2001 ). At age 14, however, she is surpassed by the typical boy, whose adolescent growth spurt has now started, whereas hers is almost finished. Growth in body size is complete for most girls by age 16 and for boys by age 17½, when the epiphyses at the ends of the long bones close completely (see  Chapter 7  page 217 ). Altogether, adolescents add 10 to 11 inches in height and 50 to 75 pounds—nearly 50 percent of adult body weight.  Figure 11.1  on  page 364  illustrates pubertal changes in general body growth.


Sex differences in pubertal growth are obvious among these 11-year-olds. Compared with the boys, the girls are taller and more mature-looking.

Body Proportions.

During puberty, the cephalocaudal growth trend of infancy and childhood reverses. The hands, legs, and feet accelerate first, followed by the torso, which accounts for most of the adolescent height gain. This pattern helps explain why early adolescents often appear awkward and out of proportion—long-legged, with giant feet and hands.

Large sex differences in body proportions also appear, caused by the action of sex hormones on the skeleton. Boys’ shoulders broaden relative to the hips, whereas girls’ hips broaden relative to the shoulders and waist. Of course, boys also end up larger than girls, and their legs are longer in relation to the rest of the body—mainly because boys have two extra years of preadolescent growth, when the legs are growing the fastest.

Muscle–Fat Makeup and Other Internal Changes.

Sabrina worried about her weight because compared with her later-developing girlfriends, she had accumulated much more fat. Around age 8, girls start to add fat on their arms, legs, and trunk, a trend that accelerates between ages 11 and 16. In contrast, arm and leg fat decreases in adolescent boys. Although both sexes gain in muscle, this increase is much greater in boys, who develop larger skeletal muscles, hearts, and lung capacity (Rogol, Roemmich, & Clark,  2002 ). Also, the number of red blood cells—and therefore the ability to carry oxygen from the lungs to the muscles—increases in boys but not in girls. Altogether, boys gain far more muscle strength than girls, a difference that contributes to teenage boys’ superior athletic performance (Ramos et al.,  1998 ).


FIGURE 11.1 Body growth during adolescence.

Because the pubertal growth spurt takes place earlier for girls than for boys, Kate reached her adult body size earlier than Steven. Rapid pubertal growth is accompanied by large sex differences in body proportions.

Motor Development and Physical Activity

Puberty brings steady improvements in gross motor performance, but the pattern of change differs for boys and girls. Girls’ gains are slow and gradual, leveling off by age 14. In contrast, boys show a dramatic spurt in strength, speed, and endurance that continues through the teenage years. By midadolescence, few girls perform as well as the average boy in running speed, broad jump, or throwing distance, and practically no boys score as low as the average girl (Haywood & Getchell,  2005 ; Malina & Bouchard,  1991 ).

Because girls and boys are no longer well-matched physically, gender-segregated physical education usually begins in middle school. Athletic options for both sexes expand as new sports—including track and field, wrestling, tackle football, weight lifting, floor hockey, archery, tennis, and golf—are added to the curriculum.

Among boys, athletic competence is strongly related to peer admiration and self-esteem. Some adolescents become so obsessed with physical prowess that they turn to performance-enhancing drugs. In recent large-scale studies, about 8 percent of U.S. high school seniors, mostly boys, reported using creatine, an over-the-counter substance that enhances short-term muscle power but carries a risk of serious side effects, including muscle tissue disease, brain seizures, and heart irregularities (Castillo & Comstock,  2007 ). About 2 percent of seniors, again mostly boys, have taken anabolic steroids or a related substance, androstenedione—powerful prescription medications that boost muscle mass and strength (Johnston et al.,  2012 ). Teenagers usually obtain steroids illegally, ignoring side effects, which range from acne, excess body hair, and high blood pressure to mood swings, aggressive behavior, and damage to the liver, circulatory system, and reproductive organs (Casavant et al.,  2007 ). Coaches and health professionals should inform teenagers of the dangers of these performance-enhancing substances.

In 1972, the U.S. federal government required schools receiving public funds to provide equal opportunities for males and females in all educational programs, including athletics. Since then, high school girls’ sports participation has increased, but it still falls far short of boys’. According to a recent survey of all 50 U.S. state high school athletic associations, 41 percent of sports participants are girls, 59 percent boys (National Federation of State High School Associations,  2012 ). In  Chapter 9 , we saw that girls get less encouragement and recognition for athletic achievement, a pattern that starts early and persists into the teenage years (see  page 296 ).

Furthermore, when researchers followed a large, representative sample of U.S. youths from ages 9 to 15, physical activity declined by about 40 minutes per day each year until, at age 15, less than one-third met the U.S. government recommendation of at least 60 minutes of moderate to strenuous physical activity per day (see  Figure 11.2 ) (Nader et al.,  2008 ). In high school, only 57 percent of U.S. boys and 47 percent of girls are enrolled in any physical education, with 31 percent of all students experiencing a daily physical education class (U.S. Department of Health and Human Services,  2012f ).

Besides improving motor performance, sports and exercise influence cognitive and social development. Interschool and intramural athletics provide important lessons in teamwork, problem solving, assertiveness, and competition. And regular, sustained physical activity—which required physical education can ensure—is associated with lasting physical and mental health benefits and enjoyment of sports and exercise (Brand et al.,  2010 ). In one study, participating in team or individual sports at age 14 at least once a week for girls and twice a week for boys predicted high physical activity rates at age 31. Endurance sports, such as running and cycling—activities that do not require expensive equipment or special facilities—were especially likely to continue into adulthood (Tammelin et al.,  2003 ). And adolescent exertion during exercise, defined as sweating and breathing heavily, is one of the best predictors of adult physical exercise, perhaps because it fosters high physical self-efficacy—belief in one’s ability to sustain an exercise program (Motl et al.,  2002 ; Telama et al.,  2005 ).


High school girls’ participation in sports has increased but still falls far short of boys’. Yet athletic participation yields many benefits—not just gains in motor skills but important lessons in teamwork, problem solving, assertiveness, and competition.


FIGURE 11.2 Decline in physical activity from ages 9 to 15 among U.S. boys and girls.

In a large representative sample of youths followed over six years, time spent exercising dropped sharply until, at age 15, most youths did not meet government recommendations of at least 60 minutes of moderate to vigorous physical activity per day. At all ages, boys spent more time exercising than girls.

(Adapted from Nader et al., 2008.)

Sexual Maturation

Accompanying rapid body growth are changes in physical features related to sexual functioning. Some, called  primary sexual characteristics , involve the reproductive organs (ovaries, uterus, and vagina in females; penis, scrotum, and testes in males). Others, called  secondary sexual characteristics , are visible on the outside of the body and serve as additional signs of sexual maturity (for example, breast development in females and the appearance of underarm and pubic hair in both sexes). As  Table 11.1  on  page 366  shows, these characteristics develop in a fairly standard sequence, although the ages at which each begins and is completed vary greatly. Typically, pubertal development takes about four years, but some adolescents complete it in two years, whereas others take five to six years.

Sexual Maturation in Girls.

Female puberty usually begins with the budding of the breasts and the growth spurt.  Menarche , or first menstruation, typically occurs around age 12½ for North American girls, 13 for Western Europeans. But the age range is wide, from 10½ to 15½ years. Following menarche, breast and pubic hair growth are completed, and underarm hair appears.

Notice in  Table 11.1  that nature delays sexual maturity until the girl’s body is large enough for childbearing; menarche takes place after the peak of the height spurt. As an extra measure of security, for 12 to 18 months following menarche, the menstrual cycle often occurs without the release of an ovum from the ovaries (Archibald, Graber, & Brooks-Gunn,  2006 ; Bogin,  2001 ). But this temporary period of sterility does not occur in all girls, and it does not provide reliable protection against pregnancy.

TABLE 11.1 Pubertal Development in North American Girls and Boys

Breasts begin to “bud”   10 8–13 Testes begin to enlarge   11.5 9.5–13.5
Height spurt begins   10 8–13 Pubic hair appears   12 10–15
Pubic hair appears   10.5 8–14 Penis begins to enlarge image10 12 10.5–14.5
Peak strength spurt image11 11.6 9.5–14 Height spurt begins   12.5 10.5–16
Peak height spurt   11.7 10–13.5 Spermarche (first ejaculation) occurs   13.5 12–16
Menarche (first menstruation) occurs   12.5 10.5–14 Peak height spurt   14 12.5–15.5
Peak weight spurt   12.7 10–14 Peak weight spurt   14 12.5–15.5
Adult stature reached   13 10–16 Facial hair begins to grow   14 12.5–15.5
Pubic hair growth completed   14.5 14–15 Voice begins to deepen   14 12.5–15.5
Breast growth completed   15 10–17 Penis and testes growth completed   14.5 12.5–16
        Peak strength spurt   15.3 13–17
        Adult stature reached   15.5 13.5–17.5
        Pubic hair growth completed   15.5 14–17

Sources: Chumlea et al., 2003; Herman-Giddens, 2006; Rogol, Roemmich, & Clark, 2002; Rubin et al., 2009; Wu, Mendola, & Buck, 2002.

Photos:(left) © Laura Dwight Photography; (right) Rob Melnychuk/Taxi/Getty Images

Sexual Maturation in Boys.

The first sign of puberty in boys is the enlargement of the testes (glands that manufacture sperm), accompanied by changes in the texture and color of the scrotum. Pubic hair emerges soon after, about the same time the penis begins to enlarge (Rogol, Roemmich, & Clark,  2002 ).

As  Table 11.1  reveals, the growth spurt occurs much later in the sequence of pubertal events for boys than for girls. When it reaches its peak around age 14, enlargement of the testes and penis is nearly complete, and underarm hair appears. So do facial and body hair, which increase gradually for several years. Another landmark of male physical maturity is the deepening of the voice as the larynx enlarges and the vocal cords lengthen. (Girls’ voices also deepen slightly.) Voice change usually takes place at the peak of the male growth spurt and is often not complete until puberty is over (Archibald, Graber, & Brooks-Gunn,  2006 ).

While the penis is growing, the prostate gland and seminal vesicles (which together produce semen, the fluid containing sperm) enlarge. Then, around age 13½,  spermarche , or first ejaculation, occurs (Rogol, Roemmich, & Clark,  2002 ). For a while, the semen contains few living sperm. So, like girls, boys have an initial period of reduced fertility.

Individual Differences in Pubertal Growth

Heredity contributes substantially to the timing of pubertal changes. Identical twins are more similar than fraternal twins in attainment of most pubertal milestones (Eaves et al.,  2004 ; Mustanski et al.,  2004 ). Nutrition and exercise also make a difference. In females, a sharp rise in body weight and fat may trigger sexual maturation. Fat cells release a protein called leptin, which is believed to signal the brain that the girl’s energy stores are sufficient for puberty—a likely reason that breast and pubic hair growth and menarche occur earlier for heavier and, especially, obese girls. In contrast, girls who begin rigorous athletic training at an early age or who eat very little (both of which reduce the percentage of body fat) usually experience later puberty (Kaplowitz,  2007 ; Lee et al.,  2007 ; Rubin et al.,  2009 ). Few studies, however, report a link between body fat and puberty in boys.

Variations in pubertal growth also exist among regions of the world and among SES and ethnic groups. Physical health plays a major role. In poverty-stricken regions where malnutrition and infectious disease are common, menarche is greatly delayed, occurring as late as age 14 to 16 in many parts of Africa. Within developing countries, girls from higher-income families reach menarche 6 to 18 months earlier than those living in economically disadvantaged homes (Parent et al.,  2003 ).

But in industrialized nations where food is abundant, the joint roles of heredity and environment in pubertal growth are apparent. For example, breast and pubic hair growth begin, on average, around age 9 in African-American girls—a year earlier than in Caucasian-American girls. And African-American girls reach menarche about six months earlier, around age 12. Although widespread overweight and obesity in the black population contribute, a genetically influenced faster rate of physical maturation is also involved. Black girls usually reach menarche before white girls of the same age and body weight (Chumlea et al.,  2003 ; Herman-Giddens,  2006 ; Hillard,  2008 ).

Early family experiences may also affect pubertal timing. One theory suggests that humans have evolved to be sensitive to the emotional quality of their childhood environments. When children’s safety and security are at risk, it is adaptive for them to reproduce early. Research indicates that girls and (less consistently) boys with a history of family conflict, harsh parenting, or parental separation tend to reach puberty early. In contrast, those with warm, stable family ties reach puberty relatively late (Belsky et al.,  2007 ; Bogaert,  2005 ; Ellis,  2004 ; Ellis & Essex,  2007 ; Mustanski et al.,  2004 ; Tremblay & Frigon,  2005 ). Critics offer an alternative explanation—that mothers who reached puberty early are more likely to bear children earlier, which increases the likelihood of marital conflict and separation (Mendle et al.,  2006 ). But two longitudinal studies confirm the former chain of influence among girls: from adverse family environments in childhood to earlier pubertal timing to increased sexual risk taking (Belsky et al.,  2010 ; James et al.,  2012 ).

In the research we have considered, threats to emotional health accelerate puberty, whereas threats to physical health delay it. A  secular trend , or generational change, in pubertal timing lends added support to the role of physical well-being in pubertal development. In industrialized nations, age of menarche declined steadily—by about 3 to 4 months per decade—from 1900 to 1970, a period in which nutrition, health care, sanitation, and control of infectious disease improved greatly. Boys, too, have reached puberty earlier in recent decades (Herman-Giddens et al.,  2012 ). And as developing nations make socioeconomic progress, they also show secular gains (Ji & Chen,  2008 ).

In the United States and a few European countries, soaring rates of overweight and obesity are responsible for a modest, continuing trend toward earlier menarche (Kaplowitz,  2006 ; Parent et al.,  2003 ). A worrisome consequence is that girls who reach sexual maturity at age 10 or 11 will feel pressure to act much older than they are. As we will see shortly, early-maturing girls are at risk for unfavorable peer involvements, including sexual activity.

Brain Development

The physical transformations of adolescence include major changes in the brain. Brain-imaging research reveals continued pruning of unused synapses in the cerebral cortex, especially in the prefrontal cortex. In addition, linkages between the two cerebral hemispheres through the corpus callosum, and between the prefrontal cortex and other areas in the cerebral cortex and the inner brain (including the amygdala), expand, myelinate, and attain rapid communication. As a result, the prefrontal cortex becomes a more effective “executive”—overseeing and managing the integrated functioning of various areas, yielding more complex, flexible, and adaptive thinking and behavior (Blakemore & Choudhury,  2006 ; Lenroot & Giedd,  2006 ). Consequently, adolescents gain in diverse cognitive skills, including processing speed and executive function.

But these advances occur gradually over the teenage years. fMRI evidence reveals that adolescents recruit the prefrontal cortex’s network of connections with other brain areas less effectively than adults do. Because the prefrontal cognitive-control network still requires fine-tuning, teenagers’ performance on executive function tasks requiring inhibition, planning, and future orientation (rejecting a smaller immediate reward in favor of a larger delayed reward) is not yet fully mature (McClure et al.,  2004 ; Smith, Xiao, & Bechara,  2012 ; Steinberg et al.,  2009 ).


In adolescence, changes in the brain’s emotional/social network outpace development of the cognitive-control network. As a result, teenagers do not yet have the capacity to control their powerful drive for new—and sometimes risky—experiences.

Adding to these self-regulation difficulties are changes in the brain’s emotional/social network. In humans and other mammals, neurons become more responsive to excitatory neurotransmitters during puberty. As a result, adolescents react more strongly to stressful events and experience pleasurable stimuli more intensely. But because the cognitive control network is not yet functioning optimally, most teenagers find it hard to manage these powerful feelings (Ernst & Spear,  2009 ; Steinberg et al.,  2008 ). This imbalance contributes to teenagers’ drive for novel experiences, including drug taking, reckless driving, unprotected sex, and delinquent activity (Pharo et al.,  2011 ). In a longitudinal study of a nationally representative sample of 7,600 U.S. youths, researchers tracked changes in self-reported impulsivity and sensation seeking between ages 12 and 24 (Harden & Tucker-Drob,  2011 ). As  Figure 11.3  on  page 368  shows, impulsivity declined steadily with age—evidence for gradual improvement of the cognitive-control network. But sensation seeking increased from 12 to 16, followed by a more gradual decline through age 24, reflecting the challenge posed by the emotional/social network.


FIGURE 11.3 Development of impulsivity and sensation seeking from 12 to 24 years.

In this longitudinal study of a large, nationally representative U.S. sample, impulsivity declined steadily, while sensation seeking increased in early adolescence and then diminished more gradually. Findings confirm the challenge posed by the emotional/social network to the cognitive control network.

(From K. P. Harden and E. M. Tucker-Drob, 2011, “Individual Differences in the Development of Sensation Seeking and Impulsivity During Adolescence: Further Evidence for a Dual Systems Model,” Developmental Psychology, 47, p. 742. Copyright © 2011 by the American Psychological Association. Adapted with permission of the American Psychological Association.)

In sum, changes in the adolescent brain’s emotional/social network outpace development of the cognitive-control network. Only over time are young people able to effectively manage their emotions and reward-seeking behavior. Of course, wide individual differences exist in the extent to which teenagers manifest this rise in risk-taking in the form of careless, dangerous acts—some not at all, and others extremely so (Pharo et al.,  2011 ). But transformations in the adolescent brain enhance our understanding of both the cognitive advances and the worrisome behaviors of this period, along with teenagers’ need for adult patience, oversight, and guidance.

Changing States of Arousal

At puberty, revisions occur in the way the brain regulates the timing of sleep, perhaps because of increased neural sensitivity to evening light. As a result, adolescents go to bed much later than they did as children. Yet they need almost as much sleep as they did in middle childhood—about nine hours. When the school day begins early, their sleep needs are not satisfied.

This sleep “phase delay” strengthens with pubertal growth. But today’s teenagers—who often have evening social activities, part-time jobs, and bedrooms equipped with TVs, computers, and phones—get much less sleep than teenagers of previous generations (Carskadon et al.,  2002 ; Jenni, Achermann, & Carskadon,  2005 ). Sleep-deprived adolescents display declines in executive function, performing especially poorly on cognitive tasks during morning hours. And they are more likely to achieve less well in school, suffer from anxiety and depressed mood, and engage in high-risk behaviors (Dahl & Lewin,  2002 ; Hansen et al.,  2005 ; Talbot et al.,  2010 ). Sleep rebound on weekends sustains the pattern by leading to difficulty falling asleep on subsequent evenings. Later school start times ease but do not eliminate sleep loss. Educating teenagers about the importance of sleep is vital.

image14 The Psychological Impact of Pubertal Events

TAKE A MOMENT…  Think back to your late elementary and middle school days. As you reached puberty, how did your feelings about yourself and your relationships with others change? Research reveals that pubertal events affect adolescents’ self-image, mood, and interaction with parents and peers. Some outcomes are a response to dramatic physical change, whenever it occurs. Others have to do with pubertal timing.

Reactions to Pubertal Changes

Two generations ago, menarche was often traumatic. Today, girls commonly react with “surprise,” undoubtedly due to the sudden onset of the event. Otherwise, they typically report a mixture of positive and negative emotions (DeRose & Brooks-Gunn,  2006 ). Yet wide individual differences exist that depend on prior knowledge and support from family members, which in turn are influenced by cultural attitudes toward puberty and sexuality.

For girls who have no advance information, menarche can be shocking and disturbing. Unlike 50 to 60 years ago, today few girls are uninformed, a shift that is probably due to parents’ greater willingness to discuss sexual matters and to the spread of health education classes (Omar, McElderry, & Zakharia,  2003 ). Almost all girls get some information from their mothers. And some evidence suggests that compared with Caucasian-American families, African-American families may better prepare girls for menarche, treat it as an important milestone, and express less conflict over girls reaching sexual maturity—factors that lead African-American girls to react more favorably (Martin,  1996 ).

Like girls’ reactions to menarche, boys’ responses to spermarche reflect mixed feelings. Virtually all boys know about ejaculation ahead of time, but many say that no one spoke to them before or during puberty about physical changes (Omar, McElderry, & Zakharia,  2003 ). Usually they get their information from reading material or websites. Even boys who had advance information often say that their first ejaculation occurred earlier than they expected and that they were unprepared for it. As with girls, boys who feel better prepared tend to react more positively (Stein & Reiser,  1994 ). But whereas almost all girls eventually tell a friend that they are menstruating, far fewer boys tell anyone about spermarche (DeRose & Brooks-Gunn,  2006 ; Downs & Fuller,  1991 ). Overall, boys get much less social support than girls for the physical changes of puberty. They might benefit, especially, from opportunities to ask questions and discuss feelings with a sympathetic parent or health professional.

Many tribal and village societies celebrate the onset of puberty with an initiation ceremony, a ritualized announcement to the community that marks an important change in privilege and responsibility. Consequently, young people know that reaching puberty is valued in their culture. In contrast, Western societies grant little formal recognition to movement from childhood to adolescence or from adolescence to adulthood. Ceremonies such as the Jewish bar or bat mitzvah and the quinceañera in Hispanic communities (celebrating a 15-year-old girl’s sexual maturity and marriage availability), resemble initiation ceremonies, but only within the ethnic or religious subculture. They do not mark a significant change in social status in the larger society.

Instead, Western adolescents are granted partial adult status at many different ages—for example, an age for starting employment, for driving, for leaving high school, for voting, and for drinking. And in some contexts (at home and at school), they may still be regarded as children. The absence of a widely accepted marker of physical and social maturity makes the process of becoming an adult more confusing.


This 13-year-old’s bat mitzvah ceremony recognizes her as an adult with moral and religious responsibilities in the Jewish community. In the larger society, however, she will experience no change in status.

Pubertal Change, Emotion, and Social Behavior

A common belief is that puberty has something to do with adolescent moodiness and the desire for greater physical and psychological separation from parents. Let’s see what research says about these relationships.

Adolescent Moodiness.

Higher pubertal hormone levels are linked to greater moodiness, but only modestly so (Buchanan, Eccles, & Becker,  1992 ; Graber, Brooks-Gunn, & Warren,  2006 ). What other factors might contribute? In several studies, the moods of children, adolescents, and adults were monitored by having them carry electronic pagers. Over a one-week period, they were beeped at random intervals and asked to write down what they were doing, whom they were with, and how they felt.

As expected, adolescents reported less favorable moods than school-age children and adults (Larson et al.,  2002 ; Larson & Lampman-Petraitis,  1989 ). But negative moods were linked to a greater number of negative life events, such as difficulty getting along with parents, disciplinary actions at school, and breaking up with a boyfriend or girlfriend. Negative events increased steadily from childhood to adolescence, and teenagers also seemed to react to them with greater emotion than children (Larson & Ham,  1993 ). (Recall that stress reactivity is heightened by changes in the brain’s emotional/social network during puberty.)

Compared with the moods of older adolescents and adults, those of younger adolescents (ages 12 to 16) were less stable, often shifting between cheerful and sad. These mood swings were strongly related to situational changes. High points of adolescents’ days were times spent with peers and in self-chosen leisure activities. Low points tended to occur in adult-structured settings—class, job, and religious services. Furthermore, emotional highs coincided with Friday and Saturday evenings, especially in high school. Going out with friends and romantic partners increases so dramatically during adolescence that it becomes a “cultural script” for what is supposed to happen (Larson & Richards,  1998 ). Consequently, teenagers who spend weekend evenings at home often feel profoundly lonely.

Fortunately, frequent reports of negative mood level off in late adolescence (Natsuaki, Biehl, & Ge,  2009 ). And overall, teenagers with supportive family and peer relationships more often report positive and less often negative moods than their agemates with few social supports (Weinstein et al.,  2006 ). In contrast, poorly adjusted young people—with low self-esteem, conduct difficulties, or delinquency—tend to react with stronger negative emotion to unpleasant daily experiences, perhaps compounding their adjustment problems (Schneiders et al.,  2006 ).

Parent–Child Relationships.

Sabrina’s father noticed that as his children entered adolescence, they kept their bedroom doors closed, resisted spending time with the family, and became more argumentative. Sabrina and her mother squabbled over Sabrina’s messy room (“It’s my room, Mom. You don’t have to live in it!”). And Sabrina protested the family’s regular weekend visit to Aunt Gina’s (“Why do I have to go every week?”). Research in cultures as diverse as the United States and Turkey shows that puberty is related to a rise in intensity of parent–child conflict, which persists into middle adolescence (Gure, Ucanok, & Sayil,  2006 ; Laursen, Coy, & Collins,  1998 ; McGue et al.,  2005 ).

Why should a youngster’s more adultlike appearance trigger these disputes? The association may have adaptive value. Among nonhuman primates, the young typically leave the family group around the time of puberty. The same is true in many nonindustrialized cultures (Caine,  1986 ; Schlegel & Barry,  1991 ). Departure of young people discourages sexual relations between close blood relatives. But adolescents in industrialized nations, who are still economically dependent on parents, cannot leave the family. Consequently, a substitute seems to have emerged: psychological distancing.

As children become physically mature, they demand to be treated in adultlike ways. And as we will see, adolescents’ new powers of reasoning may also contribute to a rise in family tensions. Parent–adolescent disagreements focus largely on everyday matters such as driving, dating partners, and curfews (Adams & Laursen,  2001 ). But beneath these disputes lie serious concerns: parental efforts to protect teenagers from substance use, auto accidents, and early sex. The larger the gap between parents’ and adolescents’ views of teenagers’ readiness for new responsibilities, the more they quarrel (Deković, Noom, & Meeus,  1997 ).

Parent–daughter conflict tends to be more intense than conflict with sons, perhaps because parents place more restrictions on girls (Allison & Schultz,  2004 ). But most disputes are mild and diminish by late adolescence. Parents and teenagers display both conflict and affection, and they usually agree on important values, such as honesty and the importance of education. And as the teenage years conclude, parent–adolescent interactions are less hierarchical, setting the stage for mutually supportive relationships in adulthood (Laursen & Collins,  2009 ).


Interview several parents and/or their 12- to 14-year-olds about recent changes in parent–child relationships. Has conflict increased? Over what topics?

Pubertal Timing

“All our children were early maturers,” said Franca during the parents’ discussion group. “The three boys were tall by age 12 or 13, but it was easier for them. They felt big and important. Sabrina was skinny as a little girl, but now she says she is too fat and needs to diet. She thinks about boys and doesn’t concentrate on her schoolwork.”

Findings of several studies match the experiences of Sabrina and her brothers. Both adults and peers viewed early-maturing boys as relaxed, independent, self-confident, and physically attractive. Popular with agemates, they tended to hold leadership positions in school and to be athletic stars. In contrast, late-maturing boys expressed more anxiety and depressed mood than their on-time counterparts (Brooks-Gunn,  1988 ; Huddleston & Ge,  2003 ). But early-maturing boys, though viewed as well-adjusted, reported more psychological stress, depressed mood, and problem behaviors (sexual activity, smoking, drinking, aggression, delinquency) than both their on-time and later-maturing agemates (Ge, Conger, & Elder,  2001 ; Natsuaki, Biehl, & Ge,  2009 ; Susman & Dorn,  2009 ).


African-American early-maturing girls are more likely to report a positive body image than their Caucasian counterparts. Perhaps because their families and friends tend to welcome menarche, they may escape the adjustment difficulties commonly associated with early pubertal timing.

In contrast, early-maturing girls were unpopular, withdrawn, lacking in self-confidence, anxious (especially about others’ negative evaluations), and prone to depression, and they held few leadership positions (Blumenthal et al.,  2011 ; Ge, Conger, & Elder,  1996 ; Graber, Brooks-Gunn, & Warren,  2006 ; Jones & Mussen,  1958 ). And like early-maturing boys, they were more involved in deviant behavior (smoking, drinking, sexual activity) (Caspi et al.,  1993 ; Dick et al.,  2000 ; Ge et al.,  2006 ). In contrast, their later-maturing counterparts were regarded as physically attractive, lively, sociable, and leaders at school. In one study of several hundred eighth graders, however, negative effects were not evident among early-maturing African-American girls, whose families—and perhaps friends as well—tend to be more unconditionally welcoming of menarche (see  page 365 ) (Michael & Eccles,  2003 ).

Two factors largely account for these trends: (1) how closely the adolescent’s body matches cultural ideals of physical attractiveness, and (2) how well young people fit in physically with their peers.

The Role of Physical Attractiveness.

TAKE A MOMENT…  Flip through your favorite popular magazine. You will see evidence of our society’s view of an attractive female as thin and long-legged and of a good-looking male as tall, broad-shouldered, and muscular. The female image is a girlish shape that favors the late developer. The male image fits the early-maturing boy.

Consistent with these preferences, early-maturing Caucasian girls tend to report a less positive  body image —conception of and attitude toward their physical appearance—than their on-time and late-maturing agemates. Compared with African-American and Hispanic girls, Caucasian girls are more likely to have internalized the cultural ideal of female attractiveness. Most want to be thinner (Rosen,  2003 ; Stice, Presnell, & Bear-man,  2001 ; Williams & Currie,  2000 ). Although boys are less consistent, early, rapid maturers are more likely to be satisfied with their physical characteristics (Alsaker,  1995 ; Sinkkonen, Anttila, & Siimes,  1998 ).

Body image is a strong predictor of young people’s self-esteem (Harter,  2006 ). But the negative effects of pubertal timing on body image and—as we will see next—emotional adjustment are greatly amplified when accompanied by other stressors (Stice,  2003 ).

The Importance of Fitting in with Peers.

Physical status in relation to peers also explains differences in adjustment between early and late maturers. From this perspective, early-maturing girls and late-maturing boys have difficulty because they fall at the extremes of physical development and feel out of place when with their agemates. Not surprisingly, adolescents feel most comfortable with peers who match their own level of biological maturity (Stattin & Magnusson,  1990 ).

Because few agemates of the same pubertal status are available, early-maturing adolescents of both sexes seek out older companions, who often encourage them into activities they are not ready to handle emotionally. And hormonal influences on the brain’s emotional/social network are stronger for early maturers, further magnifying their receptiveness to sexual activity, drug and alcohol use, and delinquent acts (Ge et al.,  2002 ; Steinberg,  2008 ). Perhaps as a result, early maturers of both sexes more often report feeling stressed and show declines in academic performance (Mendle, Turkheimer, & Emery,  2007 ; Natsuaki, Biehl, & Ge,  2009 ).

At the same time, the young person’s context greatly increases the likelihood that early pubertal timing will lead to negative outcomes. Early maturers in economically disadvantaged neighborhoods are especially vulnerable to establishing ties with deviant peers, which heightens their defiant, hostile behavior. And because families in such neighborhoods tend to be exposed to chronic, severe stressors and to have few social supports, these early maturers are also more likely to experience harsh, inconsistent parenting, which, in turn, predicts both deviant peer associations and antisocial behavior (Ge et al.,  2002  2011 ).

Long-Term Consequences.

Do the effects of pubertal timing last? Follow-ups reveal that early-maturing girls, especially, are prone to lasting difficulties. In one study, depression subsided by age 13 in early-maturing boys but tended to persist in early-maturing girls (Ge et al.,  2003 ). In another study, which followed young people from ages 14 to 24, early-maturing boys again showed good adjustment. But early-maturing girls reported poorer-quality relationships with family and friends, smaller social networks, and lower life satisfaction into early adulthood than their on-time counterparts (Graber et al.,  2004 ).

Recall that childhood family conflict and harsh parenting are linked to earlier pubertal timing, more so for girls than for boys (see  page 367 ). Perhaps many early-maturing girls enter adolescence with emotional and social difficulties. As the stresses of puberty interfere with school performance and lead to unfavorable peer pressures, poor adjustment extends and deepens (Graber,  2003 ). Clearly, interventions that target at-risk early-maturing youths are needed. These include educating parents and teachers and providing adolescents with counseling and social supports so they will be better prepared to handle the emotional and social challenges of this transition.


REVIEW Summarize the impact of pubertal timing on adolescent development.

CONNECT How might adolescent moodiness contribute to psychological distancing between parents and adolescents? (Hint: Think about bidirectional influences in parent–child relationships.)

APPLY As a school-age child, Chloe enjoyed leisure activities with her parents. Now, at age 14, she spends hours in her room and resists going on weekend family excursions. Explain Chloe’s behavior.

REFLECT Recall your own reactions to the physical changes of puberty. Are they consistent with research findings? Explain.

image17 Health Issues

The arrival of puberty brings new health issues related to the young person’s efforts to meet physical and psychological needs. As adolescents attain greater autonomy, their personal decision making becomes important, in health as well as other areas. Yet none of the health concerns we are about to discuss can be traced to a single cause. Rather, biological, psychological, family, peer, and cultural factors jointly contribute.

Nutritional Needs

When their sons reached puberty, Franca and Antonio reported a “vacuum cleaner effect” in the kitchen as the boys routinely emptied the refrigerator. Rapid body growth leads to a dramatic increase in nutritional requirements, at a time when the diets of many young people are the poorest. Of all age groups, adolescents are the most likely to skip breakfast (a practice linked to obesity), eat on the run, and consume empty calories (Ritchie et al.,  2007 ; Striegel-Moore & Franko,  2006 ). Fast-food restaurants, where teenagers often gather, have begun to offer some healthy menu options. But adolescents need guidance in choosing these alternatives. Eating fast food and school purchases from snack bars and vending machines is strongly associated with consumption of soft drinks and foods high in fat and sugar, indicating that teenagers often make unhealthy food choices (Bowman et al.,  2004 ; Kubik et al.,  2003 ).

The most common nutritional problem of adolescence is iron deficiency. Iron requirements increase to a maximum during the growth spurt and remain high among girls because of iron loss during menstruation. A tired, irritable teenager may be suffering from anemia rather than unhappiness and should have a medical checkup. Most adolescents do not get enough calcium and are also deficient in riboflavin (vitamin B2) and magnesium, both of which support metabolism (Cavadini, Siega-Riz, & Popkin,  2000 ).

Frequency of family meals is strongly associated with greater intake of fruits, vegetables, grains, and calcium-rich foods and reduced soft drink and fast-food consumption (Burgess-Champoux et al.,  2009 ; Fiese & Schwartz,  2008 ). But compared to families with younger children, those with adolescents eat fewer meals together. In addition to their other benefits (see  page 63  in  Chapter 2  and  page 291  in  Chapter 9 ), family meals can greatly improve teenagers’ diets.

Adolescents—especially girls concerned about their weight—tend to be attracted to fad diets. Unfortunately, most are too limited in nutrients and calories to be healthy for fast-growing, active teenagers (Donatelle,  2012 ). Parents should encourage young people to consult a doctor or dietitian before trying any special diet.

Eating Disorders

Concerned about her daughter’s desire to lose weight, Franca explained to Sabrina that she was really quite average in build for an adolescent girl and reminded her that her Italian ancestors had considered a plump female body more beautiful than a thin one. Girls who reach puberty early, who are very dissatisfied with their body image, and who grow up in homes where concern with weight and thinness is high are at risk for eating problems. Severe dieting is the strongest predictor of the onset of an eating disorder in adolescence (Lock & Kirz,  2008 ). The two most serious are anorexia nervosa and bulimia nervosa.

Anorexia Nervosa.

Anorexia nervosa  is a tragic eating disorder in which young people starve themselves because of a compulsive fear of getting fat. It affects about 1 percent of North American and Western European teenage girls. During the past half-century, cases have increased sharply, fueled by cultural admiration of female thinness. Anorexia nervosa is equally common in all SES groups, but Asian-American, Caucasian-American, and Hispanic girls are at greater risk than African-American girls, who tend to be more satisfied with their size and shape (Granillo, Jones-Rodriguez, & Carvajal,  2005 ; Ozer & Irwin,  2009 ; Steinhausen,  2006 ). Boys account for 10 to 15 percent of anorexia cases; about half of these are gay or bisexual young people who are uncomfortable with a strong, muscular appearance (Raevuori et al.,  2009 ; Robb & Dadson,  2002 ).


Aiva, a 16-year-old anorexia nervosa patient, is shown at left on the day she entered treatment—weighing just 77 pounds—and, at right, after a 10-week treatment program. Less than 50 percent of young people with anorexia recover fully.

Individuals with anorexia have an extremely distorted body image. Even after they have become severely underweight, they see themselves as too heavy. Most go on self-imposed diets so strict that they struggle to avoid eating in response to hunger. To enhance weight loss, they exercise strenuously.

In their attempt to reach “perfect” slimness, individuals with anorexia lose between 25 and 50 percent of their body weight. Because a normal menstrual cycle requires about 15 percent body fat, either menarche does not occur or menstrual periods stop. Malnutrition causes pale skin, brittle discolored nails, fine dark hairs all over the body, and extreme sensitivity to cold. If it continues, the heart muscle can shrink, the kidneys can fail, and irreversible brain damage and loss of bone mass can occur. About 6 percent of individuals with anorexia die of the disorder, as a result of either physical complications or suicide (Katzman,  2005 ).

Forces within the person, the family, and the larger culture give rise to anorexia nervosa. Identical twins share the disorder more often than fraternal twins, indicating a genetic influence. Abnormalities in neurotransmitters in the brain, linked to anxiety and impulse control, may make some individuals more susceptible (Kaye,  2008 ; Lock & Kirz,  2008 ). Many young people with anorexia have unrealistically high standards for their own behavior and performance, are emotionally inhibited, and avoid intimate ties outside the family. Consequently, they are often excellent students who are responsible and well-behaved. But as we have also seen, the societal image of “thin is beautiful” contributes to the poor body image of many girls—especially early-maturing girls, who are at greatest risk for anorexia nervosa (Hogan & Strasburger,  2008 ).

In addition, parent–adolescent interactions reveal problems related to adolescent autonomy. Often the mothers of these girls have high expectations for physical appearance, achievement, and social acceptance and are overprotective and controlling. Fathers tend to be emotionally distant. These parental attributes may contribute to affected girls’ persistent anxiety and fierce pursuit of perfection in achievement, respectable behavior, and thinness (Kaye,  2008 ). Nevertheless, it remains unclear whether maladaptive parent–child relationships precede the disorder, emerge in response to it, or both.

Because individuals with anorexia typically deny or minimize the seriousness of their disorder, treating it is difficult (Couturier & Lock,  2006 ). Hospitalization is often necessary to prevent life-threatening malnutrition. The most successful treatment is family therapy plus medication to reduce anxiety and neurotransmitter imbalances (Robin & Le Grange,  2010 ; Treasure & Schmidt,  2005 ). Still, less than 50 percent of young people with anorexia recover fully. For many, eating problems continue in less extreme form. About 10 percent show signs of a less severe, but nevertheless debilitating, disorder: bulimia nervosa.

Bulimia Nervosa.

In  bulimia nervosa , young people (again, mainly girls, but gay and bisexual boys are also vulnerable) engage in strict dieting and excessive exercise accompanied by binge eating, often followed by deliberate vomiting and purging with laxatives (Herzog, Eddy, & Beresin,  2006 ; Wichstrøm,  2006 ). Bulimia typically appears in late adolescence and is more common than anorexia nervosa, affecting about 2 to 4 percent of teenage girls, only 5 percent of whom previously suffered from anorexia.

Twin studies show that bulimia, like anorexia, is influenced by heredity (Klump, Kaye, & Strober,  2001 ). Overweight and early menarche increase the risk. Some adolescents with bulimia, like those with anorexia, are perfectionists. But most are impulsive, sensation-seeking young people who lack self-control in many areas, engaging in petty shoplifting, alcohol abuse, and other risky behaviors (Kaye,  2008 ). And although girls with bulimia, like those with anorexia, are pathologically anxious about gaining weight, they may have experienced their parents as disengaged and emotionally unavailable rather than controlling (Fairburn & Harrison,  2003 ).

In contrast to young people with anorexia, those with bulimia usually feel depressed and guilty about their abnormal eating habits and desperately want help. As a result, bulimia is usually easier to treat than anorexia, through support groups, nutrition education, training in changing eating habits, and anti-anxiety, antidepressant, and appetite-control medication (Hay & Bacaltchuk,  2004 ).


Sabrina’s 16-year-old brother Louis and his girlfriend Cassie hadn’t planned to have intercourse—it “just happened.” But before and after, a lot of things passed through their minds. After they had dated for three months, Cassie began to wonder, “Will Louis think I’m normal if I don’t have sex with him? If he wants to and I say no, will I lose him?” Both young people knew their parents wouldn’t approve. In fact, when Franca and Antonio noticed how attached Louis was to Cassie, they talked to him about the importance of waiting and the dangers of pregnancy. But that Friday evening, Louis and Cassie’s feelings for each other seemed overwhelming. “If I don’t make a move,” Louis thought, “will she think I’m a wimp?”


Cultural attitudes will profoundly affect the way these young teenagers, who are just beginning to explore their sexual attraction to each other, learn to manage sexuality in social relationships.

With the arrival of puberty, hormonal changes—in particular, the production of androgens in young people of both sexes—lead to an increase in sex drive (Halpern, Udry, & Suchindran,  1997 ). In response, adolescents become very concerned about managing sexuality in social relationships. New cognitive capacities involving perspective taking and self-reflection affect their efforts to do so. Yet like the eating behaviors we have just discussed, adolescent sexuality is heavily influenced by the young person’s social context.

The Impact of Culture.

TAKE A MOMENT…  When did you first learn the “facts of life”—and how? Was sex discussed openly in your family, or was it treated with secrecy? Exposure to sex, education about it, and efforts to limit the sexual curiosity of children and adolescents vary widely around the world.

Despite the prevailing image of sexually free adolescents, sexual attitudes in North America are relatively restrictive. Typically, parents provide little or no information about sex, discourage sex play, and rarely talk about sex in children’s presence. When young people become interested in sex, only about half report getting information from parents about intercourse, pregnancy prevention, and sexually transmitted disease. Many parents avoid meaningful discussions about sex out of fear of embarrassment or concern that the adolescent will not take them seriously (Wilson et al.,  2010 ). Yet warm, open give-and-take is associated with teenagers’ adoption of parents’ views and with reduced sexual risk taking (Jaccard, Dodge, & Dittus,  2003 ; Usher-Seriki, Bynum, & Callands,  2008 ).

Adolescents who do not get information about sex from their parents are likely to learn from friends, books, magazines, movies, TV, and the Internet (Jaccard, Dodge, & Dittus,  2002 ; Sutton et al.,  2002 ). On prime-time TV shows, which adolescents watch more than other TV offerings, 80 percent of programs contain sexual content. Most depict partners as spontaneous and passionate, taking no steps to avoid pregnancy or sexually transmitted disease, and experiencing no negative consequences (Roberts, Henriksen, & Foehr,  2004 ). In several studies, teenagers’ media exposure to sexual content predicted current sexual activity, intentions to be sexually active in the future, and subsequent sexual activity, pregnancies, and sexual harassment behaviors (offensive name-calling or touching, pressuring a peer for a date) even after many other relevant factors were controlled (Brown & L’Engle,  2009 ; Chandra et al.,  2008 ; Roberts, Henriksen, & Foehr,  2009 ).

Not surprisingly, adolescents who are prone to early sexual activity choose to consume more sexualized media (Steinberg & Monahan,  2011 ). The Internet is an especially hazardous “sex educator.” In a survey of a large sample of U.S. 10- to 17-year-old Web users, 42 percent said they had viewed online pornographic websites (images of naked people or people having sex) while surfing the Internet in the past 12 months. Of these, 66 percent indicated they had encountered the images accidentally and did not want to view them (Wolak, Mitchell, & Finkelhor,  2007 ). Youths who felt depressed, had been bullied by peers, or were involved in delinquent activities had more encounters with Internet pornography, which may have intensified their adjustment problems.

Consider the contradictory messages young people receive. On one hand, adults express disapproval of sex at a young age and outside of marriage. On the other hand, the social environment extols sexual excitement, experimentation, and promiscuity. American teenagers are left bewildered, poorly informed about sexual facts, and with little sound advice on how to conduct their sex lives responsibly.

Adolescent Sexual Attitudes and Behavior.

Although differences between subcultural groups exist, sexual attitudes of U.S. adolescents and adults have become more liberal over the past 40 years. Compared with a generation ago, more people believe that sexual intercourse before marriage is all right, as long as two people are emotionally committed to each other (ABC News,  2004 ; Hoff, Greene, & Davis,  2003 ). During the past two decades, adolescents have swung back slightly toward more conservative sexual beliefs, largely in response to the risk of sexually transmitted disease, especially AIDS, and to teenage sexual abstinence programs sponsored by schools and religious organizations (Akers et al.,  2011 ; Ali & Scelfo,  2002 ).

Trends in adolescents’ sexual behavior are consistent with their attitudes. Rates of extramarital sex among U.S. young people rose for several decades, declined during the 1990s, and then stabilized (U.S. Department of Health and Human Services,  2012f ). Nevertheless, as  Figure 11.4  illustrates, a substantial percentage of U.S. young people are sexually active by ninth grade (age 14 to 15).


FIGURE 11.4 U.S. adolescents who report ever having had sexual intercourse.

Many young adolescents are sexually active—more than in other Western nations. Boys tend to have their first intercourse earlier than girls. By the end of high school, rates of boys and girls having had sexual intercourse are similar.

(From U.S. Department of Health and Human Services, 2012f.)

Overall, teenage sexual activity rates are similar in the United States and other Western countries: Nearly half of adolescents have had intercourse. But quality of sexual experiences differs. U.S. youths become sexually active earlier than their Canadian and European counterparts (Boyce et al.,  2006 ; U.S. Department of Health and Human Services,  2012f ). And about 18 percent of U.S. adolescent boys and 13 percent of girls—more than in other Western nations—have had sexual relations with four or more partners in the past year. Most teenagers, however, have had only one or two sexual partners by the end of high school.

Characteristics of Sexually Active Adolescents.

Early and frequent teenage sexual activity is linked to personal, family, peer, and educational characteristics. These include childhood impulsivity, weak sense of personal control over life events, early pubertal timing, parental divorce, single-parent and stepfamily homes, large family size, little or no religious involvement, weak parental monitoring, disrupted parent–child communication, sexually active friends and older siblings, poor school performance, lower educational aspirations, and tendency to engage in norm-violating acts, including alcohol and drug use and delinquency (Coley, Votruba-Drzal, & Schindler,  2009 ; Crockett, Raffaelli, & Shen,  2006 ; Siebenbruner, Zimmer-Gembeck, & Egeland,  2007 ; Zimmer-Gembeck & Helfand,  2008 ).

Because many of these factors are associated with growing up in a low-income family, it is not surprising that early sexual activity is more common among young people from economically disadvantaged homes. Living in a neighborhood high in physical deterioration, crime, and violence also increases the likelihood that teenagers will be sexually active (Ge et al.,  2002 ). In such neighborhoods, social ties are weak, adults exert little oversight and control over adolescents’ activities, and negative peer influences are widespread. In fact, the high rate of sexual activity among African-American teenagers—60 percent report having had sexual intercourse, compared with 47 percent of all U.S. young people—is largely accounted for by widespread poverty in the black population (Darroch, Frost, & Singh,  2001 ; U.S. Department of Health & Human Services,  2012b ).

Contraceptive Use.

Although adolescent contraceptive use has increased in recent years, about 20 percent of sexually active teenagers in the United States are at risk for unintended pregnancy because they do not use contraception consistently (see  Figure 11.5 ) (Fortenberry,  2010 ). Why do so many fail to take precautions? Typically, teenagers respond, “I was waiting until I had a steady boyfriend,” or “I wasn’t planning to have sex.” As we will see when we take up adolescent cognitive development, although adolescents can consider multiple possibilities when faced with a problem, they often fail to apply this advanced reasoning to everyday situations.


FIGURE 11.5 Contraceptive use by sexually active 15-year-olds in 10 industrialized nations.

Sexually active U.S. teenagers are less likely to use contraception (condom, contraceptive pill, or both) consistently than teenagers in other industrialized nations.

(Adapted from Godeau et al., 2008; U.S. Department of Health and Human Services, 2012f.)

One reason is that advances in perspective taking lead teenagers, for a time, to be extremely concerned about others’ opinions of them. Recall how Cassie and Louis each worried about what the other would think if they decided not to have sex. Also, in the midst of everyday social pressures, adolescents often overlook the potential consequences of risky behaviors. And many teenagers—especially those from troubled, low-income families—do not have realistic expectations about the impact of early parenthood on their current and future lives (Stevens-Simon, Sheeder, & Harter,  2005 ).

As these findings suggest, the social environment also contributes to teenagers’ reluctance to use contraception. Those without the rewards of meaningful education and work are especially likely to engage in irresponsible sex, sometimes within relationships characterized by exploitation. About 12 percent of U.S. girls and 5 percent of boys say they were pressured to have intercourse when they were unwilling (U.S. Department of Health and Human Services,  2012f ).

In contrast, teenagers who report good relationships with parents and who talk openly with them about sex and contraception are more likely to use birth control (Henrich et al.,  2006 ; Kirby,  2002a ). But few adolescents believe their parents would be understanding and supportive. School sex education classes, as well, often leave teenagers with incomplete or incorrect knowledge. Some do not know where to get birth control counseling and devices. And those engaged in high-risk sexual behaviors are especially likely to worry that a doctor or family planning clinic might not keep their visits confidential (Lehrer et al.,  2007 ). Most of these young people forgo essential health care but continue to have sex without contraception.

Sexual Orientation.

So far, we have focused only on heterosexual behavior. About 4 percent of U.S. 15- to 44-year-olds identify as lesbian, gay, or bisexual (Mosher, Chandra, & Jones,  2005 ). An unknown number experience same-sex attraction but have not come out to friends or family (see the  Social Issues: Health  box on  page 376 ). Adolescence is an equally crucial time for the sexual development of these young people, and societal attitudes, again, loom large in how well they fare.

Heredity makes an important contribution to homosexuality: Identical twins of both sexes are much more likely than fraternal twins to share a homosexual orientation; so are biological (as opposed to adoptive) relatives (Kendler et al.,  2000 ; Kirk et al.,  2000 ). Furthermore, male homosexuality tends to be more common on the maternal than on the paternal side of families, suggesting that it may be X-linked (see  Chapter 2 ). Indeed, one gene-mapping study found that among 40 pairs of homosexual brothers, 33 (82 percent) had an identical segment of DNA on the X chromosome (Hamer et al.,  1993 ). One or several genes in that region might predispose males to become homosexual.

How might heredity lead to homosexuality? According to some researchers, certain genes affect the level or impact of prenatal sex hormones, which modify brain structures in ways that induce homosexual feelings and behavior (Bailey et al.,  1995 ; LeVay,  1993 ). Keep in mind, however, that environmental factors can also alter prenatal hormones. Girls exposed prenatally to very high levels of androgens or estrogens—either because of a genetic defect or from drugs given to the mother to prevent miscarriage—are more likely to become lesbian or bisexual (Meyer-Bahlburg et al.,  1995 ). Furthermore, gay men tend to be later in birth order and to have a higher-than-average number of older brothers (Blanchard & Bogaert,  2004 ). One possibility is that mothers with several male children sometimes produce antibodies to androgens, reducing the prenatal impact of male sex hormones on the brains of later-born boys.

Social Issues: Health Lesbian, Gay, and Bisexual Youths: Coming Out to Oneself and Others

Cultures vary as much in their acceptance of homosexuality as in their approval of extramarital sex. In the United States, homosexuals are stigmatized, as shown by the degrading language often used to describe them. This makes forming a sexual identity a much greater challenge for lesbian, gay, and bisexual youths than for their heterosexual counterparts.

Wide variations in sexual identity formation exist, depending on personal, family, and community factors. Yet interviews with gay and lesbian adolescents and adults reveal that many (though not all) move through a three-phase sequence in coming out to themselves and others.

Feeling Different

Many gay men and lesbians recall feeling different from other children when they were young. Typically, this first sense of their biologically determined sexual orientation appears between ages 6 and 12, in play interests more like those of the other gender (Rahman & Wilson,  2003 ). Boys may find that they are less interested in sports, more drawn to quieter activities, and more emotionally sensitive than other boys; girls that they are more athletic and active than other girls.

By age 10, many of these children start to engage in sexual questioning—wondering why the typical heterosexual orientation does not apply to them. Often, they experience their sense of being different as deeply distressing. Compared with children who are confident of their homosexuality, sexual-questioning children report greater anxiety about peer relationships and greater dissatisfaction with their biological gender over time (Carver, Egan, & Perry,  2004 ).


With the arrival of puberty, feeling different clearly encompasses feeling sexually different. In research on ethnically diverse lesbian, gay, and bisexual youths, awareness of a same-sex physical attraction occurred, on average, between ages 11 and 12 for boys and 14 and 15 for girls, perhaps because adolescent social pressures toward heterosexuality are particularly intense for girls (D’Augelli,  2006 ; Diamond,  1998 ).

Realizing that homosexuality has personal relevance generally sparks additional confusion. A few adolescents resolve their discomfort by crystallizing a gay, lesbian, or bisexual identity quickly, with a flash of insight into their sense of being different. But most experience an inner struggle and a deep sense of isolation—outcomes intensified by lack of role models and social support (D’Augelli,  2002 ; Safren & Pantalone,  2006 ).

Some throw themselves into activities they associate with heterosexuality. Boys may go out for athletic teams; girls may drop softball and basketball in favor of dance. And many homosexual youths (more females than males) try heterosexual dating, sometimes to hide their sexual orientation and at other times to develop intimacy skills that they later apply to same-sex relationships (D’Augelli,  2006 ; Dubé, Savin-Williams, & Diamond,  2001 ). Those who are extremely troubled and guilt-ridden may escape into alcohol, drugs, and suicidal thinking. Suicide attempts are unusually high among lesbian, gay, and bisexual young people (Morrow,  2006 ; Teasdale & Bradley-Engen,  2010 ).


By the end of adolescence, the majority of gay, lesbian, and bisexual teenagers accept their sexual identity. But they face another crossroad: whether to tell others. The powerful stigma against their sexual orientation leads some to decide that disclosure is impossible: While self-defining as gay, they otherwise “pass” as heterosexual (Savin-Williams,  2001 ). When homosexual youths do come out, they often face intense hostility, including verbal abuse and physical attacks, because of their sexual orientation. These experiences trigger intense emotional distress, depression, suicidal thoughts, school truancy, and drug use in victims (Almeida et al.,  2009 ; Birkett, Espelage, & Koenig,  2009 ).

Nevertheless, many young people eventually acknowledge their sexual orientation publicly, usually by telling trusted friends first. Once teenagers establish a same-sex sexual or romantic relationship, many come out to parents. Although few parents respond with severe rejection, lesbian, gay, and bisexual young people report lower levels of family support than their heterosexual agemates (Needham & Austin,  2010 ; Savin-Williams & Ream,  2003 ). Yet parental understanding is the strongest predictor of favorable adjustment—including reduced internalized homophobia, or societal prejudice turned against the self (D’Augelli, Grossman, & Starks,  2008 ).

When people react positively, coming out strengthens the young person’s view of homosexuality as a valid, meaningful, and fulfilling identity. Contact with other gays and lesbians is important for reaching this phase, and changes in society permit many adolescents in urban areas to attain it earlier than their counterparts did a decade or two ago. Gay and lesbian communities exist in large cities, along with specialized interest groups, social clubs, religious groups, newspapers, and periodicals. But teenagers in small towns and rural areas may have difficulty meeting other homosexuals and finding a supportive environment. These adolescents have a special need for caring adults and peers who can help them find self- and social acceptance.


Lesbian, gay, bisexual, and transgender high school students and their allies participate in an annual Youth Pride Festival and March. When peers react with acceptance, coming out strengthens the young person’s view of homosexuality as a valid and fulfilling identity.

Lesbian, gay, and bisexual teenagers who succeed in coming out to themselves and others integrate their sexual orientation into a broader sense of identity, a process we will address in  Chapter 12 . As a result, energy is freed for other aspects of psychological growth. In sum, coming out can foster many facets of adolescent development, including self-esteem, psychological well-being, and relationships with family and friends.

Stereotypes and misconceptions about homosexuality persist. For example, most homosexual adolescents are not “gender-deviant” in dress or behavior. And attraction to members of the same sex is not limited to lesbian, gay, and bisexual teenagers. About 50 to 60 percent of adolescents who report having engaged in homosexual acts identify as heterosexual (Savin-Williams & Diamond,  2004 ). And in a study of lesbian, bisexual, and “unlabeled” young women over a 10-year period, most reported stable proportions of same-sex versus other-sex attractions over time, providing evidence that bisexuality is not, as often assumed, a transient state (Diamond,  2008 ).

The evidence to date suggests that genetic and prenatal biological influences are largely responsible for homosexuality. In our evolutionary past, homosexuality may have served the adaptive function of reducing aggressive competition for other-sex mates (Rahman & Wilson,  2003 ).

Sexually Transmitted Diseases

Sexually active adolescents, both homosexual and heterosexual, are at risk for sexually transmitted diseases (STDs). Adolescents have the highest rates of STDs of all age groups. Despite a recent decline in STDs in the United States, one out of five to six sexually active teenagers contracts one of these illnesses each year—a rate three or more times as high as that of Canada and Western Europe (Centers for Disease Control and Prevention,  2011d ). Teenagers at greatest risk are the same ones most likely to engage in irresponsible sexual behavior: poverty-stricken young people who feel a sense of hopelessness (Niccolai et al.,  2004 ). Left untreated, STDs can lead to sterility and life-threatening complications.

By far the most serious STD is AIDS. In contrast to other Western nations, where the incidence of AIDS among people under age 30 is low, about 15 percent of U.S. AIDS cases occur in young people between ages 20 and 29. Because AIDS symptoms typically do not emerge until 8 to 10 years after infection with the HIV virus, nearly all these cases originated in adolescence. Drug-abusing teenagers who share needles and male adolescents who have sex with HIV-positive same-sex partners account for most cases, but heterosexual spread of the disease remains high, especially among teenagers with more than one partner in the previous 18 months. It is at least twice as easy for a male to infect a female with any STD, including HIV, as for a female to infect a male. Currently, females account for about 25 percent of new U.S. cases among adolescents and young adults (Centers for Disease Control and Prevention,  2011b ).

As a result of school courses and media campaigns, most adolescents are aware of basic facts about AIDS. But they have limited understanding of other STDs, tend to underestimate their own susceptibility, and are poorly informed about how to protect themselves (Copen, Chandra, & Martinez,  2012 ; Ethier et al.,  2003 ; Centers for Disease Control and Prevention,  2007 ).

Furthermore, high school students report engaging in oral sex as early and about as often as intercourse. But few report consistently using STD protection during oral sex, which is a significant mode of transmission of several STDs (Copen, Chandra, & Martinez,  2012 ). Concerted efforts are needed to educate young people about the full range of STDs and risky sexual behaviors.

Adolescent Pregnancy and Parenthood

Cassie didn’t get pregnant after having sex with Louis, but some of her classmates were less fortunate. About 727,000 U.S. teenage girls (12,000 of them younger than age 15)—an estimated 20 percent of those who had sexual intercourse—became pregnant in the most recently reported year. Despite a decline of almost one-half since 1990, the U.S. adolescent pregnancy rate remains higher than that of most other industrialized countries (Ventura, Curtin, & Abma,  2012 ). Three factors heighten the incidence of adolescent pregnancy: (1) Effective sex education reaches too few teenagers; (2) convenient, low-cost contraceptive services for adolescents are scarce; and (3) many families live in poverty, which encourages young people to take risks without considering the future implications of their behavior.

Because about one-fourth of U.S. adolescent pregnancies end in abortion, the number of American teenage births is considerably lower than it was 50 years ago (Ventura, Curtin, & Abma,  2012 ). Still, it is up to nine times higher than in most other developed nations (see  Figure 11.6 ). But teenage parenthood is a much greater problem today because adolescents are far less likely to marry before childbirth. In 1960, only 15 percent of teenage births were to unmarried females, compared with 87 percent today (Child Trends,  2011 ). Increased social acceptance of single motherhood, along with the belief of many teenage girls that a baby might fill a void in their lives, means that very few girls give up their infants for adoption.


FIGURE 11.6 Birth rates among 15- to 19-year-olds in 15 industrialized nations.

The U.S. adolescent birth rate greatly exceeds that of most other industrialized nations.

(From Centers for Disease Control and Prevention, 2011c.)

Correlates and Consequences of Adolescent Parenthood.

Becoming a parent is especially challenging for adolescents, who have not yet established a clear sense of direction for their own lives. Life conditions and personal attributes jointly contribute to adolescent childbearing and also interfere with teenagers’ capacity to parent effectively.

Teenage parents are far more likely to be poor than age-mates who postpone parenthood. Their backgrounds often include low parental warmth and involvement, domestic violence and child abuse, repeated parental divorce and remarriage, adult models of unmarried parenthood, and residence in neighborhoods where other adolescents also display these risks. Girls at risk for early pregnancy do poorly in school, engage in alcohol and drug use, have a childhood history of aggressive and antisocial behavior, associate with deviant peers, and experience high rates of depression (Elfenbein & Felice,  2003 ; Hillis et al.,  2004 ; Luster & Haddow,  2005 ). A high percentage of out-of-wedlock births are to low-income ethnic minority teenagers. Many turn to early parenthood as a way to move into adulthood when educational and career avenues are unavailable.

The lives of expectant teenagers, already troubled in many ways, tend to worsen in several respects after the baby is born:

· ● Educational attainment. Parenthood before age 18 reduces the likelihood of finishing high school. Only about 70 percent of U.S. adolescent mothers graduate, compared with 95 percent of girls who wait to become parents (National Women’s Law Center,  2007 ).

· ● Marital patterns. Teenage motherhood reduces the chances of marriage and, for those who do marry, increases the likelihood of divorce compared with peers who delay child-bearing (Moore & Brooks-Gunn,  2002 ). Consequently, teenage mothers spend more of their parenting years as single parents. About 35 percent become pregnant again within two years. Of these, about half go on to deliver a second child (Child Trends,  2011 ).

· ● Economic circumstances. Because of low educational attainment, marital instability, and poverty, many teenage mothers are on welfare or work in unsatisfying, low-paid jobs. Similarly, many adolescent fathers are unemployed or earn too little to provide their children with basic necessities (Bunting & McAuley,  2004 ). An estimated 50 percent have committed illegal offenses resulting in imprisonment (Elfenbein & Felice,  2003 ). And for both mothers and fathers, reduced educational and occupational attainment often persists well into adulthood (Taylor,  2009 ).

Because many pregnant teenage girls have inadequate diets, smoke, use alcohol and other drugs, and do not receive early prenatal care, their babies often experience pregnancy and birth complications—especially preterm and low birth weight (Khashan, Baker, & Kenny,  2010 ). And compared with adult mothers, adolescent mothers know less about child development, have unrealistically high expectations of infants, perceive their babies as more difficult, interact less effectively with them, and more often engage in child abuse (Moore & Florsheim,  2001 ; Pomerleau, Scuccimarri, & Malcuit,  2003 ; Sieger & Renk,  2007 ). Their children tend to score low on intelligence tests, achieve poorly in school, and engage in disruptive social behavior.

Furthermore, adolescent parenthood frequently is repeated in the next generation (Brooks-Gunn, Schley, & Hardy,  2002 ). In longitudinal studies that followed mothers—some who gave birth as teenagers, others who postponed parenting—and their children for several decades, mothers’ age at first childbirth strongly predicted the age at which their daughters and sons became parents. The researchers found that adolescent parenthood was linked to a set of related unfavorable family conditions and personal characteristics that negatively influenced development over an extended time and, therefore, often transferred to the next generation. Among influential factors was father absence (Barber, 2001a; Campa & Eckenrode,  2006 ; Meade, Kershaw, & Ickovics,  2008 ). Consistent with findings reported earlier for sexual activity and pregnancy, far greater intergenerational continuity, especially for daughters, occurred when teenage mothers remained unmarried.

Even when children born to teenage mothers do not become early childbearers, their development is often compromised, in terms of likelihood of high school graduation, financial independence in adulthood, and long-term physical and mental health (Moore, Morrison, & Greene,  1997 ; Pogarsky, Thornberry, & Lizotte,  2006 ). Still, outcomes vary widely. If a teenage parent finishes high school, secures gainful employment, avoids additional births, and finds a stable partner, long-term disruptions in her own and her child’s development will be less severe.

Prevention Strategies.

Preventing teenage pregnancy means addressing the many factors underlying early sexual activity and lack of contraceptive use. Too often, sex education courses are given late (after sexual activity has begun), last only a few sessions, and are limited to a catalog of facts about anatomy and reproduction. Sex education that goes beyond this minimum does not encourage early sex, as some opponents claim (Kirby,  2002c ). It does improve awareness of sexual facts—knowledge that is necessary for responsible sexual behavior.

Knowledge, however, is not enough: Sex education must also help teenagers build a bridge between what they know and what they do. Effective sex education programs include several key elements:

· ● They teach techniques for handling sexual situations—including refusal skills for avoiding risky sexual behaviors and communication skills for improving contraceptive use—through role-playing and other activities.

· ● They deliver clear, accurate messages that are appropriate in view of participating adolescents’ culture and sexual experiences.

· ● They last long enough to have an impact.

· ● They provide specific information about contraceptives and ready access to them.

Many studies show that sex education with these components can delay the initiation of sexual activity, reduce the frequency of sex and the number of sexual partners, increase contraceptive use, change attitudes (for example, strengthen future orientation), and reduce pregnancy rates (Kirby,  2002b ; Kirby & Laris,  2009 ; Thomas & Dimitrov,  2007 ).


Contact a nearby public school district for information about its sex education curriculum. Considering research findings, do you think it is likely to be effective in delaying initiation of sexual activity and reducing adolescent pregnancy rates?

Proposals to increase access to contraceptives are the most controversial aspect of U.S. adolescent pregnancy prevention efforts. Many adults argue that placing birth control pills or condoms in the hands of teenagers is equivalent to approving of early sex. Yet sex education programs encouraging abstinence without encouraging contraceptive use have little or no impact on delaying teenage sexual activity or preventing pregnancy (Rosenbaum,  2009 ; Underhill, Montgomery, & Operario,  2007 ). In Canada and Western Europe, where community- and school-based clinics offer adolescents contraceptives and where universal health insurance helps pay for them, teenage sexual activity is no higher than in the United States—but pregnancy, childbirth, and abortion rates are much lower (Schalet,  2007 ).

Efforts to prevent adolescent pregnancy and parenthood must go beyond improving sex education and access to contraception to build academic and social competence (Allen, Seitz, & Apfel,  2007 ). In one study, researchers randomly assigned at-risk high school students either to a year-long community service class, called Teen Outreach, or to regular classroom experiences in health or social studies. In Teen Outreach, adolescents spent at least 20 hours per week in volunteer work tailored to their interests. They returned to school for discussions that focused on enhancing their community service skills and their ability to cope with everyday challenges. At the end of the school year, rates of pregnancy, school failure, and school suspension were substantially lower among participants in Teen Outreach, which fostered social skills, connection to the community, and self-respect (Allen et al.,  1997 ).

Finally, teenagers who look forward to a promising future are far less likely to engage in early and irresponsible sex. By expanding educational, vocational, and employment opportunities, society can give young people good reasons to postpone childbearing.

Intervening with Adolescent Parents.

The most difficult and costly way to deal with adolescent parenthood is to wait until it happens. Young parents need health care, encouragement to stay in school, job training, instruction in parenting and life-management skills, and high-quality, affordable child care. Schools that provide these services reduce the incidence of low-birth-weight babies, increase educational success, and prevent additional childbearing (Key et al.,  2008 ; Seitz & Apfel,  2005 ).


Early parenthood imposes lasting hardships on adolescent parents and their newborn babies. But the involvement of a caring father and a stable partnership between the parents can improve outcomes for young families.

Adolescent mothers also benefit from relationships with family members and other adults who are sensitive to their developmental needs. In one study, African-American teenage mothers who had a long-term “mentor” relationship—an aunt, neighbor, or teacher who provided emotional support and guidance—were far more likely than those without a mentor to stay in school and graduate (Klaw, Rhodes, & Fitzgerald,  2003 ). Home visiting programs are also effective. Return to  page 94  in  Chapter 3  to review the Nurse–Family Partnership, which helps launch teenage mothers and their babies on a favorable life course.

Programs focusing on fathers attempt to increase their financial and emotional commitment to the baby. Although nearly half of young fathers visit their children during the first few years, contact usually diminishes. By the time the child starts school, fewer than one-fourth have regular paternal contact. As with teenage mothers, support from family members helps fathers stay involved (Bunting & McAuley,  2004 ). Teenage mothers who receive financial and child-care assistance and emotional support from their child’s father are less distressed and more likely to sustain a relationship with him (Cutrona et al.,  1998 ; Gee & Rhodes,  2003 ). And infants with lasting ties to their teenage fathers show better long-term adjustment (Florsheim & Smith,  2005 ; Furstenberg & Harris,  1993 ).

Substance Use and Abuse

At age 14, Louis waited until he was alone at home, took some cigarettes from his uncle’s pack, and smoked. At an unchaperoned party, he and Cassie drank several cans of beer and lit up marijuana joints. Louis got little physical charge out of these experiences. A good student, who was well-liked by peers and got along well with his parents, he did not need drugs as an escape valve. But he knew of other teenagers who started with alcohol and cigarettes, moved on to harder substances, and eventually were hooked.

Teenage alcohol and drug use is pervasive in industrialized nations. According to the most recent nationally representative survey of U.S. high school students, by tenth grade, 33 percent of U.S. young people have tried cigarette smoking, 58 percent drinking, and 37 percent at least one illegal drug (usually marijuana). At the end of high school, 11 percent smoke cigarettes regularly, and 27 percent have engaged in heavy drinking during the past month. About 25 percent have tried at least one highly addictive and toxic substance, such as amphetamines, cocaine, phencyclidine (PCP), Ecstasy (MDMA), inhalants, heroin, sedatives (including barbiturates), or OxyContin (a narcotic painkiller) (Johnston et al.,  2011 ).

These figures represent a substantial decline since the mid-1990s, probably resulting from greater parent, school, and media focus on the hazards of drug use. But use of marijuana, inhalants, sedatives, and OxyContin has risen slightly in recent years (Johnston et al.,  2011 ). Other drugs, such as LSD, PCP, and Ecstasy, have made a comeback as adolescents’ knowledge of their risks faded.

In part, drug taking reflects the sensation seeking of the teenage years. But adolescents also live in drug-dependent cultural contexts. They see adults relying on caffeine to stay alert, alcohol and cigarettes to cope with daily hassles, and other remedies to relieve stress, depression, and physical discomfort. And compared to a decade or two ago, today doctors more often prescribe—and parents frequently seek—medication to treat children’s problems (Olfman & Robbins,  2012 ). In adolescence, these young people may readily “self-medicate” when stressed.

Most teenagers who dabble in alcohol, tobacco, and marijuana are not headed for a life of addiction. These minimal experimenters are usually psychologically healthy, sociable, curious young people (Shedler & Block,  1990 ). As  Figure 11.7  shows, tobacco and alcohol use is somewhat greater among European than U.S. adolescents, perhaps because European adults more often smoke and drink. But illegal drug use is far more prevalent among U.S. teenagers. A greater percentage of American young people live in poverty, which is linked to family and peer contexts that promote illegal drug use. At the same time, use of diverse drugs is lower among African Americans than among Hispanic and Caucasian Americans; Native-American youths rank highest in drug taking (Johnston et al.,  2011 ). Researchers have yet to explain these variations.

Adolescent experimentation with any drug should not be taken lightly. Because most drugs impair perception and thought processes, a single heavy dose can lead to permanent injury or death. And a worrisome minority of teenagers move from substance use to abuse—taking drugs regularly, requiring increasing amounts to achieve the same effect, moving on to harder substances, and using enough to interfere with their ability to meet daily responsibilities.


FIGURE 11.7 Tenth-grade students in the United States and Europe who have used various substances.

Rates for tobacco and alcohol are based on any use in the past 30 days. Rates for marijuana and other illegal drugs are based on any lifetime use. Tobacco use and alcohol use are greater for European adolescents, whereas illegal drug use is greater for U.S. adolescents.

(Adapted from ESPAD, 2012; Johnson et al., 2011.)

Correlates and Consequences of Adolescent Substance Abuse.

Unlike experimenters, drug abusers are seriously troubled young people. Their impulsive, disruptive, hostile style is often evident in early childhood, and they are inclined to express their unhappiness through antisocial acts. Compared with other young people, their drug taking starts earlier and may have genetic roots (Dick, Prescott, & McGue,  2008 ; Tarter, Vanyukov, & Kirisci,  2008 ). But environmental factors also contribute. These include low SES, family mental health problems, parental and older sibling drug abuse, lack of parental warmth and involvement, physical and sexual abuse, and poor school performance. Especially among teenagers with family difficulties, encouragement from friends who use and provide drugs increases substance abuse (Ohannessian & Hesselbrock,  2008 ; U.S. Department of Health and Human Services,  2010c ).

Introducing drugs while the adolescent brain is still a work-in-progress can have profound, lasting consequences, impairing neurons and their connective networks. At the same time, teenagers who use substances to deal with daily stresses fail to learn responsible decision-making skills and alternative coping techniques. They show serious adjustment problems, including chronic anxiety, depression, and antisocial behavior, that are both cause and consequence of heavy drug taking (Kassel et al.,  2005 ; U.S. Department of Health and Human Services,  2010c ). And they often enter into marriage, childbearing, and the work world prematurely and fail at them—painful outcomes that further promote addictive behavior.

Prevention and Treatment.

School and community programs that reduce drug experimentation typically combine several components:

· ● They promote effective parenting, including monitoring of teenagers’ activities.

· ● They teach skills for resisting peer pressure.

· ● They reduce the social acceptability of drug taking by emphasizing health and safety risks (Cuijpers,  2002 ; Stephens et al.,  2009 ).

But given that adolescent drug taking is widespread, interventions that prevent teenagers from harming themselves and others when they do experiment are essential. Many communities offer weekend on-call transportation services that any young person can contact for a safe ride home, with no questions asked.

Because drug abuse has different roots than occasional use, different prevention strategies are required. One approach is to work with parents early, reducing family adversity and improving parenting skills, before children are old enough for drug involvement (Velleman, Templeton, & Copello,  2005 ). Programs that teach at-risk teenagers effective strategies for handling life stressors and that build competence through community service reduce alcohol and drug abuse, just as they reduce teenage pregnancy.

When an adolescent becomes a drug abuser, family and individual therapy are generally needed to treat maladaptive parent–child relationships, impulsivity, low self-esteem, anxiety, and depression. Academic and vocational training to improve life success also helps. But even comprehensive programs have alarmingly high relapse rates—from 35 to 85 percent (Brown & Ramo,  2005 ; Sussman, Skara, & Ames,  2008 ). One recommendation is to start treatment gradually, through support-group sessions that focus on reducing drug taking (Myers et al.,  2001 ). Modest improvements may increase young people’s motivation to make longer-lasting changes through intensive treatment.


Teenagers enjoy a community party sponsored by Drug Free Youth in Town (DFYIT), a substance abuse prevention program. DFYIT trains high school students as peer educators, who teach middle school students life skills and strategies for resisting peer pressure.


REVIEW Compare risk factors for anorexia nervosa and bulimia nervosa. How do treatments and outcomes differ for the two disorders?

CONNECT What unfavorable life experiences do teenagers who engage in early and frequent sexual activity have in common with those who abuse drugs?

APPLY After 17-year-old Veronica gave birth to Ben, her parents told her they didn’t have room for the baby. Veronica dropped out of school and moved in with her boyfriend, who soon left. Why are Veronica and Ben likely to experience long-term hardships?

REFLECT Describe your experiences with peer pressure to experiment with alcohol and drugs. What factors influenced your response?


One mid-December evening, a knock at the front door announced the arrival of Franca and Antonio’s oldest son, Jules, home for vacation after the fall semester of his sophomore year at college. The family gathered around the kitchen table. “How did it all go, Jules?” asked Antonio as he served slices of apple pie.

“Well, physics and philosophy were awesome,” Jules responded with enthusiasm. “The last few weeks, our physics prof introduced us to Einstein’s theory of relativity. Boggles my mind, it’s so incredibly counterintuitive.”

“Counter-what?” asked 11-year-old Sabrina.

“Counterintuitive. Unlike what you’d normally expect,” explained Jules. “Imagine you’re on a train, going unbelievably fast, like 160,000 miles a second. The faster you go, approaching the speed of light, the slower time passes and the denser and heavier things get relative to on the ground. The theory revolutionized the way we think about time, space, matter—the entire universe.”

Sabrina wrinkled her forehead, baffled by Jules’s otherworldly reasoning. “Time slows down when I’m bored, like right now, not on a train when I’m going somewhere exciting. No speeding train ever made me heavier, but this apple pie will if I eat any more of it,” Sabrina announced, leaving the table.

Sixteen-year-old Louis reacted differently. “Totally cool, Jules. So what’d you do in philosophy?”

“It was a course in philosophy of technology. We studied the ethics of futuristic methods in human reproduction. For example, we argued the pros and cons of a world in which all embryos develop in artificial wombs.”

“What do you mean?” asked Louis. “You order your kid at the lab?”

“That’s right. I wrote my term paper on it. I had to evaluate it in terms of principles of justice and freedom. I can see some advantages but also lots of dangers….”

As this conversation illustrates, adolescence brings with it vastly expanded powers of reasoning. At age 11, Sabrina finds it difficult to move beyond her firsthand experiences to a world of possibilities. Over the next few years, her thinking will acquire the complex qualities that characterize the cognition of her older brothers. Jules and Louis consider multiple variables simultaneously and think about situations that are not easily detected in the real world or that do not exist at all. As a result, they can grasp advanced scientific and mathematical principles and grapple with social and political issues. Compared with school-age children’s thinking, adolescent thought is more enlightened, imaginative, and rational.

Systematic research on adolescent cognitive development began with testing of Piaget’s ideas (Kuhn,  2009 ). Recently, information-processing research has greatly enhanced our understanding.

image27 Piaget’s Theory: The Formal Operational Stage

According to Piaget, around age 11 young people enter the  formal operational stage , in which they develop the capacity for abstract, systematic, scientific thinking. Whereas concrete operational children can “operate on reality,” formal operational adolescents can “operate on operations.” They no longer require concrete things or events as objects of thought. Instead, they can come up with new, more general logical rules through internal reflection (Inhelder & Piaget,  1955 / 1958 ). Let’s look at two major features of the formal operational stage.

Hypothetico-Deductive Reasoning

Piaget believed that at adolescence, young people first become capable of  hypothetico-deductive reasoning . When faced with a problem, they start with a hypothesis, or prediction about variables that might affect an outcome, from which they deduce logical, testable inferences. Then they systematically isolate and combine variables to see which of these inferences are confirmed in the real world. Notice how this form of problem solving begins with possibility and proceeds to reality. In contrast, concrete operational children start with reality—with the most obvious predictions about a situation. If these are not confirmed, they usually cannot think of alternatives and fail to solve the problem.

Adolescents’ performance on Piaget’s famous pendulum problem illustrates this approach. Suppose we present several school-age children and adolescents with strings of different lengths, objects of different weights to attach to the strings, and a bar from which to hang the strings (see  Figure 11.8 ). Then we ask each of them to figure out what influences the speed with which a pendulum swings through its arc.

Formal operational adolescents hypothesize that four variables might be influential: (1) the length of the string, (2) the weight of the object hung on it, (3) how high the object is raised before it is released, and (4) how forcefully the object is pushed. By varying one factor at a time while holding the other three constant, they test each variable separately and, if necessary, also in combination. Eventually they discover that only string length makes a difference.


FIGURE 11.8 Piaget’s pendulum problem.

Adolescents who engage in hypothetico-deductive reasoning think of variables that might possibly affect the speed with which a pendulum swings through its arc. Then they isolate and test each variable, as well as testing the variables in combination. Eventually they deduce that the weight of the object, the height from which it is released, and how forcefully it is pushed have no effect on the speed with which the pendulum swings through its arc. Only string length makes a difference.

In contrast, concrete operational children cannot separate the effects of each variable. They may test for the effect of string length without holding weight constant—comparing, for example, a short, light pendulum with a long, heavy one. Also, they typically fail to notice variables that are not immediately suggested by the concrete materials of the task—for example, how high the object is raised or how forcefully it is released.

Propositional Thought

A second important characteristic of Piaget’s formal operational stage is  propositional thought —adolescents’ ability to evaluate the logic of propositions (verbal statements) without referring to real-world circumstances. In contrast, children can evaluate the logic of statements only by considering them against concrete evidence in the real world.

In a study of propositional reasoning, a researcher showed children and adolescents a pile of poker chips and asked whether statements about the chips were true, false, or uncertain (Osherson & Markman,  1975 ). In one condition, the researcher hid a chip in her hand and presented the following propositions:

·  “Either the chip in my hand is green or it is not green.”

·  “The chip in my hand is green and it is not green.”

In another condition, the experimenter made the same statements while holding either a red or a green chip in full view.

School-age children focused on the concrete properties of the poker chips. When the chip was hidden, they replied that they were uncertain about both statements. When it was visible, they judged both statements to be true if the chip was green and false if it was red. In contrast, adolescents analyzed the logic of the statements. They understood that the “either-or” statement is always true and the “and” statement is always false, regardless of the poker chip’s color.

Although Piaget did not view language as playing a central role in children’s cognitive development (see  Chapter 7 ), he acknowledged its importance in adolescence. Formal operations require language-based and other symbolic systems that do not stand for real things, such as those in higher mathematics. Secondary school students use such systems in algebra and geometry. Formal operational thought also involves verbal reasoning about abstract concepts. Jules was thinking in this way when he pondered relationships among time, space, and matter in physics and wondered about justice and freedom in philosophy.

Follow-Up Research on Formal Operational Thought

Research on formal operational thought poses questions similar to those we discussed with respect to Piaget’s earlier stages: Does formal operational thinking appear earlier than Piaget expected? Do all individuals reach formal operations during their teenage years?

Are Children Capable of Hypothetico-Deductive and Propositional Thinking?

School-age children show the glimmerings of hypothetico-deductive reasoning, although they are less competent at it than adolescents. In simplified situations involving no more than two possible causal variables, 6-year-olds understand that hypotheses must be confirmed by appropriate evidence (Ruffman et al.,  1993 ). But school-age children cannot sort out evidence that bears on three or more variables at once. And as we will see when we take up information-processing research, children have difficulty explaining why a pattern of observations supports a hypothesis, even when they recognize the connection between the two.

With respect to propositional thought, when a simple set of premises defies real-world knowledge (“All cats bark. Rex is a cat. Does Rex bark?”), 4- to 6-year-olds can reason logically in make-believe play. To justify their answer, they are likely to say, “We can pretend cats bark!” (Dias & Harris,  1988 , 1990). But in an entirely verbal mode, children have great difficulty reasoning from premises that contradict reality or their own beliefs.

Consider this set of statements: “If dogs are bigger than elephants and elephants are bigger than mice, then dogs are bigger than mice.” Children younger than 10 judge this reasoning to be false because some of the relations specified do not occur in real life (Moshman & Franks,  1986 ; Pillow,  2002 ). They have more difficulty than adolescents inhibiting activation of well-learned knowledge (“Elephants are larger than dogs”) that impedes effective reasoning (Klaczynski, Schuneman, & Daniel,  2004 ; Simoneau & Markovits,  2003 ). Partly for this reason, they fail to grasp the logical necessity of propositional reasoning—that the accuracy of conclusions drawn from premises rests on the rules of logic, not on real-world confirmation.


As these students discuss problems in a social studies class, they reason logically from premises that do not refer to real-world circumstances. They are far better at propositional thought than they were as children.

As with hypothetico-deductive reasoning, in early adolescence, young people become better at analyzing the logic of propositions irrespective of their content. And as they get older, they handle problems requiring increasingly complex mental operations. In justifying their reasoning, they more often explain the logical rules on which it is based (Müller, Overton, & Reese,  2001 ; Venet & Markovits,  2001 ). But these capacities do not appear suddenly at puberty. Rather, gains occur gradually from childhood on—findings that call into question the emergence of a new stage of cognitive development at adolescence (Kuhn,  2009 ; Moshman,  2005 ).

Do All Individuals Reach the Formal Operational Stage?

TAKE A MOMENT…  Try giving one or two of the formal operational tasks just described to your friends. How well do they do? Even well-educated adults often have difficulty (Kuhn,  2009 ; Markovits & Vachon,  1990 ).

Why are so many adults not fully formal operational? One reason is that people are most likely to think abstractly and systematically on tasks in which they have had extensive guidance and practice in using such reasoning. This conclusion is supported by evidence that taking college courses leads to improvements in formal reasoning related to course content. Math and science prompt gains in propositional thought, social science in methodological and statistical reasoning (Lehman & Nisbett,  1990 ). Like concrete reasoning in children, formal operations do not emerge in all contexts at once but are specific to situation and task (Keating,  2004 ).

Individuals in tribal and village societies rarely do well on tasks typically used to assess formal operational reasoning (Cole,  1990 ). Piaget acknowledged that without the opportunity to solve hypothetical problems, people in some societies might not display formal operations. Still, researchers ask, Does formal operational thought largely result from children’s and adolescents’ independent efforts to make sense of their world, as Piaget claimed? Or is it a culturally transmitted way of thinking that is specific to literate societies and taught in school? In an Israeli study, after controlling for participants’ age, researchers found that years of schooling fully accounted for early adolescent gains in propositional thought (Artman, Cahan, & Avni-Babad,  2006 ). School tasks, the investigators speculated, provide crucial experiences in setting aside the “if … then” logic of everyday conversations that is often used to convey intentions, promises, and threats (“If you don’t do your chores, then you won’t get your allowance”) but that conflicts with the logic of academic reasoning. In school, then, adolescents encounter rich opportunities to realize their neurological potential to think more effectively.

image30 An Information-Processing View of Adolescent Cognitive Development

Information-processing theorists refer to a variety of specific mechanisms, including diverse aspects of executive function, as underlying cognitive gains in adolescence. Each was discussed in previous chapters (Kuhn,  2009 ; Kuhn & Franklin,  2006 ; Luna et al.,  2004 ). Now let’s draw them together:

· ● Attention becomes more selective (focused on relevant information) and better-adapted to the changing demands of tasks.

· ● Inhibition—both of irrelevant stimuli and of well-learned responses in situations where they are inappropriate—improves, supporting gains in attention and reasoning.

· ● Strategies become more effective, improving storage, representation, and retrieval of information.

· ● Knowledge increases, easing strategy use.

· ● Metacognition (awareness of thought) expands, leading to new insights into effective strategies for acquiring information and solving problems.

· ● Cognitive self-regulation improves, yielding better moment-by-moment monitoring, evaluation, and redirection of thinking.

· ● Speed of thinking and processing capacity increase. As a result, more information can be held at once in working memory and combined into increasingly complex, efficient representations, “opening possibilities for growth” in the capacities just listed and also improving as a result of gains in those capacities (Demetriou et al.,  2002 , p. 97).

As we look at influential findings from an information-processing perspective, we will see some of these mechanisms of change in action. And we will discover that researchers regard one of them—metacognition—as central to adolescent cognitive development.

Scientific Reasoning: Coordinating Theory with Evidence

During a free moment in physical education class, Sabrina wondered why more of her tennis serves and returns passed the net and dropped into her opponent’s court when she used a particular brand of balls. “Is it something about their color or size?” she asked herself. “Hmm … or maybe it’s their surface texture—that might affect their bounce.”

The heart of scientific reasoning is coordinating theories with evidence. Deanna Kuhn ( 2002 ) has conducted extensive research into the development of scientific reasoning, using problems that, like Piaget’s tasks, involve several variables that might affect an outcome. In one series of studies, third, sixth, and ninth graders and adults were first given evidence—sometimes consistent and sometimes conflicting with theories—and then questioned about the accuracy of each theory.

For example, participants were given a problem much like Sabrina’s: to theorize about which of several features of sports balls—size (large or small), color (light or dark), texture (rough or smooth), or presence or absence of ridges on the surface—influences the quality of a player’s serve. Next, they were told about the theory of Mr. (or Ms.) S, who believes that the ball’s size is important, and the theory of Mr. (or Ms.) C, who thinks color matters. Finally, the interviewer presented evidence by placing balls with certain characteristics in two baskets, labeled “good serve” and “bad serve” (see  Figure 11.9 ).


FIGURE 11.9 Which features of these sports balls—size, color, surface texture, or presence or absence of ridges—influence the quality of a player’s serve?

This set of evidence suggests that color might be important, since light-colored balls are largely in the good-serve basket and dark-colored balls in the bad-serve basket. But the same is true for texture! The good-serve basket has mostly smooth balls; the bad-serve basket, rough balls. Since all light-colored balls are smooth and all dark-colored balls are rough, we cannot tell whether color or texture makes a difference. But we can conclude that size and presence or absence of ridges are not important, since these features are equally represented in the good-serve and bad-serve baskets.

(Adapted from Kuhn, Amsel, & O’Loughlin, 1988.)

The youngest participants often discounted obviously causal variables, ignored evidence conflicting with their own initial judgments, and distorted evidence in ways consistent with their preferred theory. These findings, and others like them, suggest that on complex, multivariable tasks, children—instead of viewing evidence as separate from and bearing on a theory—often blend the two into a single representation of “the way things are.” Children are especially likely to overlook evidence that does not match their prior beliefs when a causal variable is implausible (like color affecting the performance of a sports ball) and when task demands (number of variables to be evaluated) are high (Yang & Tsai,  2010 ; Zimmerman,  2007 ). The ability to distinguish theory from evidence and use logical rules to examine their relationship improves steadily from childhood into adolescence, continuing into adulthood (Kuhn & Dean,  2004 ; Kuhn & Pearsall,  2000 ).

How Scientific Reasoning Develops

What factors support skill at coordinating theory with evidence? Greater working-memory capacity, permitting a theory and the effects of several variables to be compared at once, is vital. Adolescents also benefit from exposure to increasingly complex problems and to teaching that highlights critical features of scientific reasoning—for example, why a scientist’s expectations in a particular situation are inconsistent with everyday beliefs and experiences (Chinn & Malhotra,  2002 ). This explains why scientific reasoning is strongly influenced by years of schooling, whether individuals grapple with traditional scientific tasks (like the sports-ball problem) or engage in informal reasoning—for example, justifying a theory about what causes children to fail in school (Amsel & Brock,  1996 ).

Researchers believe that sophisticated metacognitive understanding is vital for scientific reasoning (Kuhn,  2009 ; Kuhn & Pease,  2006 ). When adolescents regularly pit theory against evidence over many weeks, they experiment with various strategies, reflect on and revise them, and become aware of the nature of logic. Then they apply their appreciation of logic to an increasingly wide variety of situations. The ability to think about theories, deliberately isolate variables, consider all influential variables, and actively seekdisconfirming evidence is rarely present before adolescence (Kuhn,  2000 ; Kuhn et al.,  2008 ; Moshman,  1998 ).

But adolescents and adults vary widely in scientific reasoning skills. Many continue to show a self-serving bias, applying logic more effectively to ideas they doubt than to ideas they favor (Klaczynski & Narasimham,  1998 ). Reasoning scientifically requires the metacognitive capacity to evaluate one’s objectivity—to be fair-minded rather than self-serving (Moshman,  2005 ). As we will see in  Chapter 12 , this flexible, open-minded approach is not just a cognitive attainment but a personality trait—one that assists teenagers greatly in forming an identity and developing morally.

Adolescents develop scientific reasoning skills in a similar step-by-step fashion on different types of tasks. In a series of studies, 10- to 20-year-olds were given sets of problems graded in difficulty. One set consisted of quantitative-relational tasks like the pendulum problem in  Figure 11.8 . Another contained propositional tasks like the poker chip problem on  page 384 . Still another consisted of causal-experimental tasks like the sports-ball problem in  Figure 11.9  (Demetriou et al.,  1993  1996  2002 ). In each type of task, adolescents mastered component skills in sequential order by expanding their metacognitive awareness. For example, on causal-experimental tasks, they first became aware of the many variables—separately and in combination—that could influence an outcome. This enabled them to formulate and test hypotheses. Over time, adolescents combined separate skills into a smoothly functioning system, constructing a general model that they could apply to many instances of a given type of problem.

Applying What We Know Handling Consequences of Teenagers’ New Cognitive Capacities

Thought expressed as … Suggestion
Sensitivity to public criticism Refrain from finding fault with the adolescent in front of others. If the matter is important, wait until you can speak to the teenager alone.
Exaggerated sense of personal uniqueness Acknowledge the adolescent’s unique characteristics. At opportune times, encourage a more balanced perspective by pointing out that you had similar feelings as a teenager.
Idealism and criticism Respond patiently to the adolescent’s grand expectations and critical remarks. Point out positive features of targets, helping the teenager see that all societies and people are blends of virtues and imperfections.
Difficulty making everyday decisions Refrain from deciding for the adolescent. Model effective decision making and offer diplomatic suggestions about the pros and cons of alternatives, the likelihood of various outcomes, and learning from poor choices.


Describe one or more memorable experiences from your high school classes that helped you advance in scientific reasoning—pit theory against evidence and become receptive to disconfirming evidence even for theories you favored.

Piaget underscored the role of metacognition in formal operational thought when he spoke of “operating on operations” (see  page 382 ). But information-processing findings confirm that scientific reasoning does not result from an abrupt, stagewise change. Instead, it develops gradually out of many specific experiences that require children and adolescents to match theories against evidence and reflect on and evaluate their thinking.

image32 Consequences of Adolescent Cognitive Changes

The development of increasingly complex, effective thinking leads to dramatic revisions in the way adolescents see themselves, others, and the world in general. But just as adolescents are occasionally awkward in using their transformed bodies, so they initially falter in their abstract thinking. Teenagers’ self-concern, idealism, criticism, and faulty decision making, though perplexing to adults, are usually beneficial in the long run. Applying What We Know above suggests ways to handle the everyday consequences of teenagers’ newfound cognitive capacities.

Self-Consciousness and Self-Focusing

Adolescents’ ability to reflect on their own thoughts, combined with physical and psychological changes, leads them to think more about themselves. Piaget believed that a new form of egocentrism arises, in which adolescents again have difficulty distinguishing their own and others’ perspectives (Inhelder & Piaget,  1955 / 1958 ). Piaget’s followers suggest that two distorted images of the relation between self and other appear.

The first is called the  imaginary audience , adolescents’ belief that they are the focus of everyone else’s attention and concern (Elkind & Bowen,  1979 ). As a result, they become extremely self-conscious. The imaginary audience helps explain why adolescents spend long hours inspecting every detail of their appearance and why they are so sensitive to public criticism. To teenagers, who believe that everyone is monitoring their performance, a critical remark from a parent or teacher can be mortifying.

A second cognitive distortion is the  personal fable . Certain that others are observing and thinking about them, teenagers develop an inflated opinion of their own importance—a feeling that they are special and unique. Many adolescents view themselves as reaching great heights of omnipotence and also sinking to unusual depths of despair—experiences that others cannot possibly understand (Elkind,  1994 ). One teenager wrote in her diary, “My parents’ lives are so ordinary, so stuck in a rut. Mine will be different. I’ll realize my hopes and ambitions.” Another, upset when a boyfriend failed to return her affections, rebuffed her mother’s comforting words: “Mom, you don’t know what it’s like to be in love!”


This teenager’s swagger reflects self-confidence and delight that all eyes are on him. When the personal fable engenders a view of oneself as highly capable and influential, it may help young people cope with the challenges of adolescence.

Although imaginary-audience and personal-fable ideation is common in adolescence, these distorted visions of the self do not result from egocentrism, as Piaget suggested. Rather, they are partly an outgrowth of advances in perspective taking, which cause young teenagers to be more concerned with what others think (Vartanian & Powlishta,  1996 ).

In fact, certain aspects of the imaginary audience may serve positive, protective functions. When asked why they worry about the opinions of others, adolescents responded that others’ evaluations have important real consequences—for self-esteem, peer acceptance, and social support (Bell & Bromnick,  2003 ). The idea that others care about their appearance and behavior also has emotional value, helping teenagers hold onto important relationships as they struggle to establish an independent sense of self (Vartanian,  1997 ).

With respect to the personal fable, in a study of sixth through tenth graders, sense of omnipotence predicted self-esteem and overall positive adjustment. Viewing the self as highly capable and influential helps young people cope with challenges of adolescence. In contrast, sense of personal uniqueness was modestly associated with depression and suicidal thinking (Aalsma, Lapsley, & Flannery,  2006 ). Focusing on the distinctiveness of one’s own experiences may interfere with forming close, rewarding relationships, which provide social support in stressful times. And when combined with a sensation-seeking personality, the personal fable seems to contribute to adolescent risk taking by reducing teenagers’ sense of vulnerability (Alberts, Elkind, & Ginsberg,  2007 ). Young people with high personal-fable and sensation-seeking scores tend to take more sexual risks, more often use drugs, and commit more delinquent acts than their agemates (Greene et al.,  2000 ).

Idealism and Criticism

Adolescents’ capacity to think about possibilities opens up the world of the ideal. Teenagers can imagine alternative family, religious, political, and moral systems, and they want to explore them. They often construct grand visions of a world with no injustice, discrimination, or tasteless behavior. The disparity between teenagers’ idealism and adults’ greater realism creates tension between parent and child. Envisioning a perfect family against which their parents and siblings fall short, adolescents become fault-finding critics.

Overall, however, teenage idealism and criticism are advantageous. Once adolescents come to see other people as having both strengths and weaknesses, they have a much greater capacity to work constructively for social change and to form positive, lasting relationships (Elkind,  1994 ).

Decision Making

Recall that changes in the brain’s emotional/social network outpace development of the prefrontal cortex’s cognitive-control network. Consequently, teenagers often perform less well than adults in decision making, where they must inhibit emotion and impulses in favor of thinking rationally.

Good decision making involves: (1) identifying the pros and cons of each alternative, (2) assessing the likelihood of various outcomes, (3) evaluating their choice in terms of whether their goals were met and, if not, (4) learning from the mistake and making a better future decision. When researchers modified a card game to trigger strong emotion by introducing immediate feedback about gains and losses after each choice, teenagers behaved more irrationally, taking far greater risks than adults in their twenties (Figner et al.,  2009 ). They were more influenced by the possibility of immediate reward (see  page 367 ).


These high school students attending a college fair will face many choices over the next few years. But in making decisions, teenagers are less likely than adults, to carefully weigh the pros and cons of each alternative.

Nevertheless, teenagers are less effective than adults at decision making even under “cool,” unemotional conditions (Huizenga, Crone, & Jansen,  2007 ). They less often carefully evaluate alternatives, instead falling back on well-learned intuitive judgments (Jacobs & Klaczynski,  2002 ). Consider a hypothetical problem requiring a choice, on the basis of two arguments, between taking a traditional lecture class and taking a computer-based class. One argument contains large-sample information: course evaluations from 150 students, 85 percent of whom liked the computer class. The other argument contains small-sample personal reports: complaints of two honor-roll students who both hated the computer class and enjoyed the traditional class. Most adolescents, even those who knew that selecting the large-sample argument was “more intelligent,” based their choice on the small-sample argument, which resembled the informal opinions they depend on in everyday life (Klaczynski,  2001 ).

Earlier we noted that processing skills governed by the prefrontal cortex’s cognitive-control system, such as decision making, develop gradually. But like other aspects of brain development, the cognitive-control system is affected by experience (Kuhn,  2009 ). As “first-timers” in many situations, adolescents do not have sufficient knowledge to consider pros and cons and predict likely outcomes. And after engaging in risky behavior without negative consequences, teenagers rate its benefits higher and its risks lower than peers who have not tried it—judgments that increase the chances of continued risk-taking (Halpern-Felsher et al.,  2004 ).

Over time, young people learn from their successes and failures, gather information from others about factors that affect decision making, and reflect on the decision-making process (Byrnes,  2003 ; Reyna & Farley,  2006 ). But because taking risks without experiencing harm can heighten adolescents’ sense of invulnerability, they need supervision and protection from high-risk experiences until their decision making improves.


REVIEW Describe research findings that challenge Piaget’s notion of a new stage of cognitive development at adolescence.

CONNECT How does evidence on adolescent decision making help us understand teenagers’ risk taking in sexual activity and drug use?

APPLY Clarissa, age 14, is convinced that no one appreciates how hurt she feels at not being invited to the homecoming dance. Meanwhile, 15-year-old Justine, alone in her room, pantomimes being sworn in as student body president with her awestruck parents looking on. Which aspect of the personal fable is each girl displaying? Which girl is more likely to be well-adjusted, which poorly adjusted? Explain.

REFLECT Cite examples of your own idealistic thinking or poor decision making as a teenager. How has your thinking changed?

image35 Sex Differences in Mental Abilities

Sex differences in mental abilities have sparked almost as much controversy as the ethnic and SES differences in IQ considered in  Chapter 9 . Although boys and girls do not differ in general intelligence, they do vary in specific mental abilities.

Verbal Abilities

Throughout the school years, girls attain higher scores in reading achievement and account for a lower percentage of children referred for remedial reading instruction. Girls continue to score slightly higher on tests of verbal ability in middle childhood and adolescence in every country in which assessments have been conducted (Bussière, Knighton, & Pennock,  2007 ; Mullis et al.,  2007 ; Wai et al.,  2010 ). And when verbal tests are heavily weighted with writing, girls’ advantage is large (Halpern et al.,  2007 ).

A special concern is that girls’ advantage in reading and writing achievement increases in adolescence, with boys doing especially poorly in writing—trends evident in the United States and other industrialized nations (OECD,  2010a ; U.S. Department of Education,  2007b  2010 ). These differences in literacy skills are believed to be major contributors to a widening gender gap in college enrollments. Whereas 40 years ago, males accounted for 60 percent of U.S. undergraduate students, today they are in the minority, at 43 percent (U.S. Department of Education,  2012b ).

Recall from  Chapter 5  that girls have a biological advantage in earlier development of the left hemisphere of the cerebral cortex, where language is usually localized. And fMRI research indicates that in tackling language tasks (such as deciding whether two spoken or written words rhyme), 9- to 15-year-old girls show concentrated activity in language-specific brain areas. Boys, in contrast, display more widespread activation—in addition to language areas, considerable activity in auditory and visual areas, depending on how words are presented (Burman, Bitan, & Booth,  2007 ). This suggests that girls are more efficient language processors than boys, who rely heavily on sensory brain regions and process spoken and written words differently.

But girls also receive more verbal stimulation from the preschool years through adolescence (Peterson & Roberts,  2003 ). Furthermore, children view language arts as a “feminine” subject. And as a result of the high-stakes testing movement, students today spend more time at their desks being taught in a regimented way—an approach particularly at odds with boys’ higher activity level, assertiveness, and incidence of learning problems. Clearly, reversing boys’ weakening literacy skills is a high priority, requiring a concerted effort by families, schools, and communities.

Mathematical Abilities

Studies of sex differences in mathematical abilities in the early school grades are inconsistent. Some find no disparities, others slight disparities depending on the skill assessed (Lachance & Mazzocco,  2006 ). Girls tend to be advantaged in counting, arithmetic computation, and mastery of basic concepts, perhaps because of their better verbal skills and more methodical approach to problem solving. But by late childhood to early adolescence, when math concepts become more abstract and spatial, boys start to outperform girls, with the difference especially evident on tests of complex reasoning and geometry (Bielinski & Davison,  1998 ; Gibbs,  2010 ; Lindberg et al.,  2010 ). In science achievement, too, boys’ advantage increases as problems become more difficult (Penner,  2003 ).

The male advantage is evident in most countries where males and females have equal access to secondary education. But the gap is typically small, varies considerably across nations, and has diminished over the past 30 years (Aud et al.,  2011 ; Lindberg et al.,  2010 ; U.S. Department of Education,  2009 ). Among the most capable, however, the gender gap is greater. In widely publicized research on more than 100,000 bright seventh and eighth graders invited to take the Scholastic Assessment Test (SAT), boys outscored girls on the mathematics subtest year after year. Yet even this disparity has been shrinking. A quarter-century ago, 13 times as many boys as girls scored over 700 (out of a possible 800) on the math portion of the SAT; today, the ratio is about 4 to 1 for seventh graders and 2 to 1 for high school students (Benbow & Stanley,  1983 ; Wai et al.,  2010 ).

Some researchers believe that heredity contributes substantially to the gender gap in math, especially to the tendency for more boys to be extremely talented. Accumulating evidence indicates that boys’ advantage originates in two skill areas: (1) their more rapid numerical memory, which permits them to devote more energy to complex mental operations; and (2) their superior spatial reasoning, which enhances their mathematical problem solving (Geary et al.,  2000 ; Halpern et al.,  2007 ). Longitudinal evidence on nationally representative samples of U.S. high school students tracked for a decade or more reveals that high spatial ability consistently predicts subsequent advanced educational attainment in math-intensive fields and entry into science, technology, engineering and math (STEM) careers (Wai, Lubinski, & Benbow,  2009 ). See the  Biology and Environment  box on  page 390  for further consideration of this issue.

Social pressures are also influential. Long before sex differences in math achievement appear, many children view math as a “masculine” subject. Also, many parents think boys are better at it—an attitude that encourages girls to blame their errors on lack of ability and to consider math less useful for their future lives. These beliefs, in turn, reduce girls’ confidence and interest in math and their willingness to consider STEM careers in college (Ceci & Williams,  2010 ; Kenney-Benson et al.,  2006 ; Parker et al.,  2012 ). Furthermore, stereotype threat—fear of being judged on the basis of a negative stereotype (see  pages 314  315  in  Chapter 9 )—causes girls to do worse than their abilities allow on difficult math problems (Ben-Zeev et al.,  2005 ; Muzzatti & Agnoli,  2007 ). As a result of these influences, even girls who are highly talented are less likely to develop effective math reasoning skills.

A positive sign is that today, American boys and girls reach advanced levels of high school math and science study in equal proportions—a crucial factor in reducing sex differences in knowledge and skill (Gallagher & Kaufman,  2005 ). But boys spend more time than girls with computers, and they tend to use them differently. Whereas girls typically focus on information gathering and social networking, boys more often play video games, create web pages, write computer programs, analyze data, and use graphics programs (Lenhart et al.,  2010 ; Looker & Thiessen,  2003 ; Rideout, Foehr, & Roberts,  2010 ). As a result, boys acquire more specialized computer knowledge.

Clearly, extra steps must be taken to promote girls’ interest in and confidence at math and science. As  Figure 11.10  shows, in cultures that value gender equality, sex differences in math achievement are much smaller and, in one nation, reversed! Icelandic high school girls exceed boys in math scores (Guiso et al.,  2008 ). Similarly, in countries where few individuals view science as “masculine,” secondary school girls equal or exceed boys in science achievement (Nosek et al.,  2009 ).


FIGURE 11.10 Math achievement gender gaps in 10 industrialized nations, arranged in order of increasing gender equality.

Math achievement scores are based on 15-year-olds’ performance on an identical test in each country. Country gender equality is a composite measure that includes cultural attitudes toward women, women’s participation in the labor force and in politics and government, and women’s educational attainment and economic opportunities. As country gender equality increases, boys’ advantage in math achievement declines; in Iceland, girls’ math scores exceed boys’.

(Adapted from Guiso et al., 2008.)

Biology and Environment Sex Differences in Spatial Abilities

Spatial skills are a key focus of researchers’ efforts to explain sex differences in complex mathematical reasoning. The gender gap favoring males is large for mental rotation tasks, in which individuals must rotate a three-dimensional figure rapidly and accurately inside their heads (see  Figure 11.11 ). Males also do considerably better on spatial perception tasks, in which people must determine spatial relationships by considering the orientation of the surrounding environment. Sex differences on spatial visualization tasks, involving analysis of complex visual forms, are weak or non existent. Because many strategies can be used to solve these tasks, both sexes may come up with effective procedures (Collaer & Hill,  2006 ; Voyer, Voyer, & Bryden,  1995 ).

Sex differences in spatial abilities emerge as early as the first few months of life, in male infants’ superior ability to recognize a familiar object from a new perspective—a capacity requiring mental rotation (Moore & Johnson,  2008 ; Quinn & Liben,  2008 ). The male spatial advantage is present throughout childhood, adolescence, and adulthood in many cultures (Levine et al.,  1999 ; Silverman, Choi, & Peters,  2007 ). One explanation is that heredity, perhaps by exposing the brain to androgen hormones, enhances right hemispheric functioning, giving males a spatial advantage. (Recall that for most people, spatial skills are housed in the right hemisphere of the cerebral cortex.) In support of this idea, girls and women whose prenatal androgen levels were abnormally high show superior performance on spatial rotation tasks (Berenbaum,  2001 ; Halpern & Collaer,  2005 ). And women with a male twin brother, who are exposed to slightly higher levels of prenatal androgens, outperform women with a female twin sister in spatial rotation (Heil et al.,  2011 ; Vuoksimaa et al.,  2010 ).

Why might a biologically based sex difference in spatial abilities exist? Evolutionary theorists point out that mental rotation skill predicts rapid, accurate map drawing and interpretation, areas in which boys and men do better than girls and women. Over the course of human evolution, the cognitive abilities of males became adapted for hunting, which required generating mental representations of large-scale spaces to find one’s way (Jones, Braith-waite, & Healy,  2003 ). But this explanation is controversial: Critics point out that female gatherers also needed to travel long distances to find fruits and vegetables that ripened in different seasons (Newcombe,  2007 ).

Experience also contributes to males’ superior spatial performance. Children who engage in manipulative activities, such as block play, model building, and carpentry, do better on spatial tasks (Baenninger & Newcombe,  1995 ). Furthermore, playing action video games enhances many cognitive processes important for spatial skills, including visual discrimination, speed of thinking, attention shifting, tracking of multiple objects, mental rotation, and wayfinding—gains that persist and generalize to diverse situations (Spence & Feng,  2010 ). Boys spend far more time than girls at these pursuits.

Furthermore, spatial skills respond readily to training, with improvements often larger than the sex differences themselves. But because boys and girls show similar training effects, sex differences persist (Liu et al.,  2008 ; Newcombe & Huttenlocher,  2006 ). In one study of first-graders, however, training in mental rotation strategies over several months—a more intensive approach than previously tried—led girls to reach the same performance level as boys (Tzuriel & Egozi,  2010 ). These findings suggest that the right kind of early intervention can override biologically based sex differences in spatial skills.


This 17-year-old science fair winner plans a career in physics. With supportive experiences, girls can excel in math and science.


FIGURE 11.11 Types of spatial tasks.

Large sex differences favoring males appear in mental rotation, and males do considerably better than females in spatial perception. In contrast, sex differences in spatial visualization are weak or nonexistent.

(From M. C. Linn & A. C. Petersen, 1985, “Emergence and Characterization of Sex Differences in Spatial Ability: A Meta-Analysis,” Child Development, 56, pp. 1482, 1483, 1485. © The Society for Research in Child Development. Reprinted with permission of John Wiley & Sons Ltd.)

Furthermore, a math curriculum beginning in kindergarten that teaches children how to apply effective spatial strategies—drawing diagrams, mentally manipulating visual images, searching for numerical patterns, and graphing—is vital (Nuttall, Casey, & Pezaris,  2005 ). Because girls are biased toward verbal processing, they may not attain their math and science potential unless they are taught how to think spatially.

image39 Learning in School

In complex societies, adolescence coincides with entry into secondary school. Most young people move into either a middle or a junior high school and then into a high school. With each change, academic achievement increasingly determines higher education options and job opportunities. In the following sections, we take up various aspects of secondary school life.

School Transitions

When Sabrina started middle school, she left a small, intimate, self-contained sixth-grade classroom for a much larger school. “I don’t know most of the kids in my classes, and my teachers don’t know me,” Sabrina complained to her mother at the end of the first week. “Besides, there’s too much homework. I get assignments in all my classes at once. I can’t do all this!” she shouted, bursting into tears.

Impact of School Transitions.

As Sabrina’s reactions suggest, school transitions can create adjustment problems. With each school change—from elementary to middle or junior high and then to high school—adolescents’ grades decline. The drop is partly due to tighter academic standards. At the same time, the transition to secondary school often means less personal attention, more whole-class instruction, and less chance to participate in classroom decision making (Seidman, Aber, & French,  2004 ).

It is not surprising, then, that students rate their middle-and high school learning experiences less favorably than their elementary-school experiences (Wigfield & Eccles,  1994 ). They also report that their teachers care less about them, are less friendly, grade less fairly, and stress competition more. Consequently, many young people feel less academically competent, and their liking for school and motivation decline (Barber & Olsen,  2004 ; Gutman & Midgley,  2000 ; Otis, Grouzet, & Pelletier,  2005 ).

Inevitably, students must readjust their feelings of self-confidence and self-worth as they encounter revised academic expectations and a more complex social world. In several studies that followed students across the middle- and high-school transitions, grade point average declined and feelings of anonymity increased after each school change. Girls fared less well than boys. On entering middle school, girls’ self-esteem dropped sharply, perhaps because the transition tended to coincide with other life changes: the onset of puberty and dating (Simmons & Blyth,  1987 ). And after starting high school, girls felt lonelier and more anxious than boys, and—although they were doing better academically—their grades declined more rapidly (Benner & Graham,  2009 ; Russell, Elder, & Conger,  1997 ).


On the first day of school, a teacher’s caring attention helps this sixth grader deal with the stress of moving from a small, self-contained elementary school classroom to a large middle school.

Adolescents facing added strains at either transition—family disruption, poverty, low parental involvement, or learned helplessness on academic tasks—are at greatest risk for self-esteem and academic difficulties (de Bruyn,  2005 ; Rudolph et al.,  2001 ; Seidman et al.,  2003 ). Furthermore, high-school transition is especially challenging for African-American and Hispanic students who move to a new school with substantially fewer peers of the same ethnicity (Benner & Graham,  2009 ). Under these conditions, minority adolescents report decreased feelings of belonging and school liking, and they show steeper declines in grades.

Distressed youths whose school performance either remains low or drops sharply after school transition often show a persisting pattern of poor self-esteem, motivation, and achievement. In another study, researchers compared “multiple-problem” youths (those with both academic and mental health problems), youths with difficulties in just one area (either academic or mental health), and well-adjusted youths (those doing well in both areas) across the transition to high school. Although all groups declined in grade point average, well-adjusted students continued to get high marks and multiple-problem youths low marks, with the others falling in between. And as  Figure 11.12  on  page 392  shows, the multiple-problem youths showed a far greater rise in truancy and out-of-school problem behaviors (Roeser, Eccles, & Freedman-Doan,  1999 ). For some, school transition initiates a downward spiral in academic performance and school involvement that leads to dropping out.


FIGURE 11.12 Increase in truancy and out-of-school problem behaviors across the transition to high school in four groups of students.

Well-adjusted students, students with only academic problems, and students with only mental health problems showed little change. (Good students with mental health problems actually declined in problem behaviors, so no orange bar is shown for them.) In contrast, multiple-problem students—with both academic and mental health difficulties—increased sharply in truancy and problem behaviors after changing schools from eighth to ninth grade.

(Adapted from Roeser, Eccles, & Freedman-Doan, 1999.)

Helping Adolescents Adjust to School Transitions.

As these findings reveal, school transitions often lead to environmental changes that fit poorly with adolescents’ developmental needs (Eccles & Roeser,  2009 ). They disrupt close relationships with teachers at a time when adolescents need adult support. They emphasize competition during a period of heightened self-focusing. They reduce decision making and choice as the desire for autonomy is increasing. And they interfere with peer networks as young people become more concerned with peer acceptance.


Ask several secondary school students to describe their experiences after school transition. What supports for easing the stress of transition did their teachers and school provide?

Support from parents, teachers, and peers can ease these strains. Parental involvement, monitoring, gradual autonomy granting, and emphasis on mastery rather than merely good grades are associated with better adjustment (Grolnick et al.,  2000 ; Gutman,  2006 ). Adolescents with close friends are more likely to sustain these friendships across the transition, which increases social integration and academic motivation in the new school (Aikens, Bierman, & Parker,  2005 ). Forming smaller units within larger schools promotes closer relationships with both teachers and peers and—as we will see later—greater extracurricular involvement (Seidman, Aber, & French,  2004 ). And a “critical mass” of same-ethnicity peers—according to one suggestion, at least 15 percent of the student body—helps teenagers feel socially accepted and reduces fear of out-group hostility (National Research Council,  2007 ).

Other, less extensive changes are also effective. In the first year after a school transition, homerooms can be provided in which teachers offer academic and personal counseling. Assigning students to classes with several familiar peers or a constant group of new peers strengthens emotional security and social support. In schools that took these steps, students were less likely to decline in academic performance or display other adjustment problems (Felner et al.,  2002 ).

Academic Achievement

Adolescent achievement is the result of a long history of cumulative effects. Early on, positive educational environments, both family and school, lead to personal traits that support achievement—intelligence, confidence in one’s own abilities, the desire to succeed, and high educational aspirations. Nevertheless, improving an unfavorable environment can foster resilience among poorly performing young people. See Applying What We Know on the following page for a summary of environmental factors that enhance achievement during the teenage years.

Child-Rearing Styles.

Authoritative parenting is linked to higher grades in school among adolescents varying widely in SES, just as it predicts mastery-oriented behavior in childhood. In contrast, authoritarian and permissive styles are associated with lower grades (Collins & Steinberg,  2006 ; Vazsonyi, Hibbert, & Snider,  2003 ). Uninvolved parenting (low in both warmth and maturity demands) predicts the poorest grades and worsening school performance over time (Glasgow et al.,  1997 ; Kaisa, Stattin, & Nurmi,  2000 ).

The link between authoritative parenting and adolescents’ academic competence has been confirmed in countries with diverse value systems, including Argentina, Australia, China, Hong Kong, the Netherlands, Pakistan, and Scotland (de Bruyn, Deković, & Meijnen,  2003 ; Heaven & Ciarrochi,  2008 ; Steinberg,  2001 ). In  Chapter 8 , we noted that authoritative parents adjust their expectations to children’s capacity to take responsibility for their own behavior. Adolescents whose parents engage in joint decision making, gradually permitting more autonomy with age, achieve especially well (Spera,  2005 ; Wang, Pomerantz, & Chen,  2007 ). Warmth, open discussion, firmness, and monitoring of the adolescents’ whereabouts and activities make young people feel cared about and valued, encourage reflective thinking and self-regulation, and increase awareness of the importance of doing well in school. These factors, in turn, are related to mastery-oriented attributions, effort, achievement, and high educational aspirations (Aunola, Stattin, & Nurmi,  2000 ; Gregory & Weinstein,  2004 ; Trusty,  1999 ).

Applying What We Know Supporting High Achievement in Adolescence

Factor Description
Child-rearing practices Authoritative parenting

Joint parent–adolescent decision making

Parent involvement in the adolescent’s education

Peer influences Peer valuing of and support for high achievement
School characteristics Teachers who are warm and supportive, develop personal relationships with parents, and show them how to support their teenager’s learning

Learning activities that encourage high-level thinking

Active student participation in learning activities and classroom decision making

Employment schedule Job commitment limited to less than 15 hours per week

High-quality vocational education for non-college-bound adolescents

Parent–School Partnerships.

High-achieving students typically have parents who keep tabs on their child’s progress, communicate with teachers, and make sure their child is enrolled in challenging, well-taught classes. These efforts are just as important during adolescence as they were earlier (Hill & Taylor,  2004 ). In a large, nationally representative sample of U.S. adolescents, parents’ school involvement in eighth grade strongly predicted students’ grade point average in tenth grade, beyond the influence of SES and previous academic achievement (Keith et al.,  1998 ). Parents who are in frequent contact with the school send a message to their child about the value of education, model constructive solutions to academic problems, and promote wise educational decisions.


By attending parent–teacher conferences and keeping tabs on her daughter’s academic progress, this mother sends her child a message about the importance of education and builds a bridge between the worlds of home and school.

The daily stresses of living in low-income, high-risk neighborhoods reduce parents’ energy for school involvement (Bowen, Bowen, & Ware,  2002 ). Yet stronger home–school links could relieve some of this stress. Schools can build parent–school partnerships by strengthening personal relationships between teachers and parents, tapping parents’ talents to improve the quality of school programs, and including parents in school governance so they remain invested in school goals.

Peer Influences.

Peers play an important role in adolescent achievement, in a way that relates to both family and school. Teenagers whose parents value achievement generally choose friends who share those values (Kiuru et al.,  2009 ; Woolley, Kol, & Bowen,  2009 ). For example, when Sabrina began to make new friends in middle school, she often studied with her girlfriends. Each girl wanted to do well and reinforced this desire in the others.

Peer support for high achievement also depends on the overall climate of the peer culture, which, for ethnic minority youths, is powerfully affected by the surrounding social order. In one study, integration into the school peer network predicted higher grades among Caucasians and Hispanics but not among Asians and African Americans (Faircloth & Hamm,  2005 ). Asian cultural values stress respect for family and teacher expectations over close peer ties (Chao & Tseng,  2002 ; Chen,  2005 ). African-American minority adolescents may observe that their ethnic group is worse off than the white majority in educational attainment, jobs, income, and housing. And discriminatory treatment by teachers and peers, often resulting from stereotypes that they are “not intelligent,” triggers anger, anxiety, self-doubt, declines in achievement, association with peers who are not interested in school, and increases in problem behaviors (Wong, Eccles, & Sameroff,  2003 ).

Schools that build close networks of support between teachers and peers can prevent these negative outcomes. One high school with a largely low-income ethnic minority student body (65 percent African American) reorganized into “career academies”—learning communities within the school, each offering a different career-related curriculum (for example, one focusing on health, medicine, and life sciences, another on computer technology). The smaller-school climate and common theme helped create caring teacher–student relationships and a peer culture that focused on valuing school engagement, collaborating on projects, and academic success (Conchas,  2006 ). High school graduation and college enrollment rates rose from a small minority to over 90 percent.

Social Issues: Education Media Multitasking Disrupts Attention and Learning

“Mom, I’m going to study for my biology test now,” called 16-year-old Cassie while shutting her bedroom door. Sitting down at her desk, she accessed a popular social-networking website on her laptop, donned headphones and began listening to a favorite song on her MP3 player, and placed her cell phone next to her elbow so she could hear it chime if any text messages arrived. Only then did she open her textbook and begin to read.

In a survey of a nationally representative sample of U.S. 8- to 18-year-olds, more than two-thirds reported engaging in two or more media activities at once, some or most of the time (Rideout, Foehr, & Roberts,  2010 ). Their most frequent type of media multitasking is listening to music while doing homework, but many also report watching TV or using the Internet while studying (Jeong & Fishbein,  2007 ). The presence of a television or computer in the young person’s bedroom is a strong predictor of this behavior (Foehr,  2006 ). And it extends into classrooms, where students can be seen text-messaging under their desks or surfing the Internet on cell phones.

Research confirms that media multitasking greatly reduces learning. In one experiment, participants were given two tasks: learning to predict the weather in two different cities using colored shapes as cues and keeping a mental tally of how many high-pitched beeps they heard through headphones. Half the sample performed the tasks simultaneously, the other half separately. Both groups learned to predict the weather in the two-city situation, but the multitaskers were unable to apply their learning to new weather problems (Foerde, Knowlton, & Poldrack,  2006 ).

fMRI evidence revealed that the participants working only on the weather task activated the hippocampus, which plays a vital role in explicit memory—conscious, strategic recall, which enables new information to be used flexibly and adaptively in contexts outside the original learning situation (see  page 218  in  Chapter 7 ). In contrast, the multitaskers activated subcortical areas involved in implicit memory—a shallower, automatic form of learning that takes place unconsciously.

As early as 1980, studies linked heavy media use with executive-function difficulties (Nunez-Smith et al.,  2008 ). Frequent media multitaskers, who are accustomed to continuously shifting their attention between tasks, have a harder time filtering out irrelevant stimuli when they are not multitasking (Ophir, Nass, & Wagner,  2009 ).

Beyond superficial preparation for her biology test, Cassie is likely to have trouble concentrating and strategically processing new information after turning off her computer and MP3 player. Experienced teachers often complain that compared to students of a generation ago, today’s teenagers are more easily distracted and learn less thoroughly. One teacher reflected, “It’s the way they’ve grown up—working short times on many different things at one time” (Clay,  2009 , p. 40).


Media multitasking while doing homework fragments attention, yielding superficial learning. Frequent multitaskers are likely to have trouble filtering out irrelevant stimuli even when they are not multitasking.

Finally, teenagers’ use of text messaging and e-mail to remain continuously in touch with peers—even during class and while working on homework—is an aspect of contemporary peer-group life that poses risks to achievement. Turn to the  Social Issues: Education  box above to find out about the impact of “media multitasking” on attention and learning.

School Characteristics.

Adolescents need school environments that are responsive to their expanding powers of reasoning and their emotional and social needs. Without appropriate learning experiences, their cognitive potential is unlikely to be realized.

Classroom Learning Experiences.

As noted earlier, in large, departmentalized secondary schools, many adolescents report that their classes lack warmth and supportiveness, which dampens their motivation. Of course, an important benefit of separate classes in each subject is that adolescents can be taught by experts, who are more likely to encourage high-level thinking, teach effective learning strategies, and emphasize content relevant to students’ experiences—factors that contribute to interest, effort, and achievement (Eccles,  2004 ). But many classrooms do not consistently provide stimulating, challenging teaching.

Wide variability in quality of instruction has contributed to increasing numbers of seniors who graduate from high school deficient in basic academic skills. Although the achievement gap separating African-American, Hispanic, and Native-American students from white students has declined since the 1970s, mastery of reading, writing, mathematics, and science by low-SES ethnic minority students remains disappointing (U.S. Department of Education,  2007a  2009  2010 ). Too often these young people attend underfunded schools with rundown buildings, outdated equipment, and textbook shortages. In some, crime and discipline problems receive more attention than teaching and learning. By middle school, many low-SES minority students have been placed in low academic tracks, compounding their learning difficulties.


Ability grouping, as we saw in  Chapter 9 , is detrimental during the elementary school years. At least into middle school, mixed-ability classes are desirable. They support the motivation and achievement of students who vary widely in academic progress (Gillies,  2003 ; Gillies & Ashman,  1996 ).

By high school, some grouping is unavoidable because certain aspects of education must dovetail with the young person’s future educational and vocational plans. In the United States, high school students are counseled into college preparatory, vocational, or general education tracks. Unfortunately, low-SES minority students are assigned in large numbers to noncollege tracks, perpetuating educational inequalities of earlier years.

Longitudinal research following thousands of U.S. students from eighth to twelfth grade reveals that assignment to a college preparatory track accelerates academic progress, whereas assignment to a vocational or general education track decelerates it (Hallinan & Kubitschek,  1999 ). Even in secondary schools with no formal tracking program, low-SES minority students tend to be assigned to lower course levels in most or all academic subjects, resulting in de facto (unofficial) tracking (Lucas & Behrends,  2002 ).

Breaking out of a low academic track is difficult. Track or course enrollment is generally based on past performance, which is limited by placement history. Interviews with African-American students revealed that many thought their previous performance did not reflect their ability. Yet teachers and counselors, overburdened with other responsibilities, had little time to reconsider individual cases (Ogbu,  2003 ). And compared to students in higher tracks, those in low tracks exert substantially less effort—a difference due in part to less stimulating classroom experiences (Worthy, Hungerford-Kresser, & Hampton,  2009 ).

High school students are separated into academic and vocational tracks in virtually all industrialized nations. In China, Japan, and most Western European countries, students’ placement in high school is determined by a national exam, which usually establishes the young person’s future possibilities. In the United States, students who are not assigned to a college preparatory track or who do poorly in high school can still attend college. Ultimately, however, many young people do not benefit from the more open U.S. system. By adolescence, SES differences in quality of education and academic achievement are greater in the United States than in most other industrialized countries (Marks, Cresswell, & Ainley,  2006 ). And the United States has a higher percentage of young people who see themselves as educational failures and drop out of high school (see  Figure 11.13 ).


FIGURE 11.13 High school graduation rates in 10 industrialized nations.

The United States ranks below many other developed countries.

(From OECD, 2011a.)

Part-Time Work.

In high school, about one-fourth of U.S. adolescents are employed—a greater percentage than in other developed countries. But most are middle-SES adolescents in pursuit of spending money rather than vocational exploration and training. Low-income teenagers who need to contribute to family income or to support themselves find it harder to get jobs (U.S. Department of Education,  2012b ).

Adolescents typically hold jobs that involve low-level, repetitive tasks and provide little contact with adult supervisors. A heavy commitment to such jobs is harmful. The more hours students work, the poorer their school attendance, the lower their grades, the less likely they are to participate in extracurricular activities, and the more likely they are to drop out (Marsh & Kleitman,  2005 ). Students who spend many hours at such jobs also tend to feel more distant from their parents and report more drug and alcohol use and delinquent acts (Samuolis et al.,  2011 ; Staff & Uggen,  2003 ).

In contrast, participation in work–study programs or other jobs that provide academic and vocational learning opportunities is related to positive school and work attitudes, improved achievement, and reduced delinquency (Hamilton & Hamilton,  2000 ; Staff & Uggen,  2003 ). Yet high-quality vocational preparation for non-college-bound U.S. adolescents is scarce. Unlike some European nations, the United States has no widespread training system to prepare youths for skilled business and industrial occupations and manual trades. Although U.S. federal and state governments support some job-training programs, most are too brief to make a difference and serve only a small minority of young people who need assistance.

Dropping Out

Across the aisle from Louis in math class sat Norman, who daydreamed, crumpled his notes into his pocket after class, and rarely did his homework. On test days, he twirled a rabbit’s foot for good luck but left most questions blank. Louis and Norman had been classmates since fourth grade, but they had little to do with each other. To Louis, who was quick at school-work, Norman seemed to live in another world. Once or twice a week, Norman cut class; one spring day, he stopped coming altogether.

Norman is one of about 8 percent of U.S. 16- to 24-year-olds who dropped out of high school and remain without a diploma or a GED (U.S. Department of Education,  2012b ). The dropout rate is higher among boys than girls and is particularly high among low-SES ethnic minority youths, especially Native-American and Hispanic teenagers (15 and 18 percent, respectively). The decision to leave school has dire consequences. Youths without upper secondary education have much lower literacy scores than high school graduates; they lack the skills employers value in today’s knowledge-based economy. Consequently, dropouts have much lower employment rates than high school graduates. Even when employed, dropouts are far more likely to remain in menial, low-paying jobs and to be out of work from time to time.

Factors Related to Dropping Out.

Although many dropouts achieve poorly and show high rates of norm-violating acts, a substantial number, like Norman, have few behavior problems, experience academic difficulties, and quietly disengage from school (Janosz et al.,  2000 ; Newcomb et al.,  2002 ). The pathway to dropping out starts early. Risk factors in first grade predict dropout nearly as well as risk factors in secondary school (Entwisle, Alexander, & Olson,  2005 ).

Norman had a long history of marginal-to-failing school grades and low academic self-esteem. Faced with a challenging task, he gave up, relying on luck—his rabbit’s foot—to get by. As Norman got older, he attended class less regularly, paid little attention when he was there, and rarely did his homework. He didn’t join school clubs or participate in sports. As a result, few teachers or students knew him well. By the day he left, Norman felt alienated from all aspects of school life.

As with other dropouts, Norman’s family background contributed to his problems. Compared with other students, even those with the same grade profile, dropouts are more likely to have parents who are uninvolved in their teenager’s education and engage in little monitoring of their youngster’s daily activities (Englund, Egeland, & Collins,  2008 ; Pagani et al.,  2008 ). Many are single parents, never finished high school themselves, and are unemployed.

Students who drop out often have school experiences that undermine their chances for success: grade retention, which marks them as academic failures; large, impersonal secondary schools; and classes with unsupportive teachers and few opportunities for active participation (Brown & Rodriguez,  2009 ). In such schools, rule breaking is common and often results in suspension, which—by excluding students from classes—contributes further to academic failure (Christie, Jolivette, & Nelson,  2007 ). Students in general education and vocational tracks, where teaching tends to be the least stimulating, are three times as likely to drop out as those in a college preparatory track (U.S. Department of Education,  2012 ).

Prevention Strategies.

Among the diverse strategies available for helping teenagers at risk of dropping out, several common themes are related to success:

· ● Remedial instruction and counseling that offer personalized attention. Most potential dropouts need academic assistance combined with social support—intensive remedial instruction in small classes that foster warm, caring teacher–student relationships (Christenson & Thurlow,  2004 ). In one successful approach, at-risk students are matched with retired adults, who serve as tutors, mentors, and role models in addressing academic and vocational needs (Prevatt,  2003 ).

· ● High-quality vocational training. For many marginal students, the real-life nature of vocational education is more comfortable and effective than purely academic work (Harvey,  2001 ). To work well, vocational education must carefully integrate academic and job-related instruction so students see the relevance of classroom experiences to their future goals.

· ● Efforts to address the many factors in students’ lives related to leaving school early. Programs that strengthen parent involvement, offer flexible work–study arrangements, and provide on-site child care for teenage parents can make staying in school easier for at-risk adolescents.

· ● Participation in extracurricular activities. Another way of helping marginal students is to draw them into the community life of the school. The most powerful influence on extracurricular involvement is small school size (Crosnoe, Johnson, & Elder,  2004 ; Feldman & Matjasko,  2007 ). As high school student body declines—dropping from 2,000 students to 500 to 700 students—at-risk youths are more likely to be needed to help staff activities. As a result, they feel more attached to their school. In large schools, creation of smaller “schools within schools” has the same effect.


St. Paul, Minnesota, police chief Thomas Smith warmly greets one of his student mentees following a high school fundraising event for a charitable organization. Support from a caring adult and extracurricular involvement are effective ways to prevent school dropout.

Moderate (but not excessive) participation in arts, community service, or vocational development activities promotes improved academic performance, reduced antisocial behavior, more favorable self-esteem and initiative, and increased peer acceptance (Fredricks,  2012 ; Fredricks & Eccles,  2006 ). Adolescents with academic, emotional, and social problems are especially likely to benefit (Marsh & Kleitman,  2002 ).

As we conclude our discussion of academic achievement, let’s place the school dropout problem in historical perspective. Over the second half of the twentieth century, the percentage of U.S. young people completing high school by age 24 increased steadily, from less than 50 percent to just over 90 percent. Although many dropouts get caught in a vicious cycle in which their lack of self-confidence and skills prevents them from seeking further education and training, about one-third return to finish their secondary education within a few years (U.S. Department of Education,  2012b ). And some extend their schooling further as they come to realize how essential education is for a rewarding job and a satisfying adult life.


REVIEW List ways that parents can promote their adolescent’s academic achievement. Explain why each is effective.

CONNECT How are educational practices that prevent school dropout similar to those that improve learning for adolescents in general?

APPLY Tanisha is finishing sixth grade. She can either continue in her current school through eighth grade or switch to a much larger seventh- to ninth-grade middle school. Which choice would you suggest, and why?

REFLECT Describe your own experiences in making the transition to middle or junior high school and then to high school. What did you find stressful? What helped you adjust?

image46 SUMMARY


Conceptions of Adolescence ( p. 362 )

· How have conceptions of adolescence changed over the past century?

· ● Adolescence is the transition between childhood and adulthood. Early theorists viewed adolescence as either a biologically determined period of storm and stress or entirely influenced by the social environment. Contemporary researchers view adolescence as a joint product of biological, psychological, and social forces.

· ● In industrialized societies, adolescence is greatly extended.

Puberty: The Physical Transition to Adulthood ( p. 363 )

Describe body growth, motor performance, and sexual maturation during puberty.

· ● Hormonal changes under way in middle childhood initiate puberty, on average, two years earlier for girls than for boys. The first outward sign is the growth spurt. As the body enlarges, girls’ hips and boys’ shoulders broaden. Girls add more fat, boys more muscle.

· ● Puberty brings slow, gradual improvements in gross-motor performance for girls, dramatic gains for boys. Nevertheless, participation in regular physical activity declines sharply with age.

· ● At puberty, changes in primary and secondary sexual characteristics accompany rapid body growth. Menarche occurs late in the girl’s sequence of pubertal events, after the growth spurt peaks. In boys, the peak in growth occurs later, preceded by enlargement of the sex organs and spermarche.

What factors influence the timing of puberty?

· ● Heredity, nutrition, exercise, and overall physical health influence the timing of puberty. The emotional quality of family experiences may play a role.

· ● A secular trend toward earlier puberty has occurred in industrialized nations as physical well-being increased. In some countries, rising obesity rates have extended this trend.

What changes in the brain take place during adolescence?

· ● Pruning of unused synapses in the cerebral cortex continues, and linkages between areas of the brain expand and myelinate. As the prefrontal cortex becomes a more effective “executive,” adolescents gradually gain in processing speed and executive function. But performance on tasks requiring inhibition, planning, and future orientation is not yet fully mature.

· ● During puberty, neurons become more responsive to excitatory neurotransmitters, heightening emotional reactivity and reward-seeking. Changes in the brain’s emotional/social network outpace development of the cognitive-control network, resulting in self-regulation difficulties. image47

· ● Revisions also occur in brain regulation of sleep timing, leading to a sleep “phase delay.” Sleep deprivation contributes to poorer achievement, depressed mood, and high-risk behaviors.

The Psychological Impact of Pubertal Events ( p. 368 )

· Explain adolescents’ reactions to the physical changes of puberty.

· ● Girls typically react to menarche with mixed emotions, although those who receive advance information and support from family members respond more positively. Boys, who receive little social support for pubertal changes, react to spermarche with mixed feelings.

· ● Besides higher hormone levels, negative life events and adult-structured situations are associated with adolescents’ negative moods. Psychological distancing between parent and child at puberty may be a modern substitute for physical departure from the family.

Describe the impact of pubertal timing on adolescent adjustment, noting sex differences.

· ● Early-maturing boys and late-maturing girls have a more positive body image and usually adjust well. In contrast, early-maturing girls and late-maturing boys tend to experience emotional and social difficulties, which—for girls—persist into early adulthood.

Health Issues ( p. 371 )

· Describe nutritional needs during adolescence, and cite factors related to eating disorders.

· ● Nutritional requirements increase with rapid body growth, and vitamin and mineral deficiencies may result from poor eating habits. Frequency of family meals is associated with healthy eating.

· ● Early puberty, certain personality traits, maladaptive family interactions, and societal emphasis on thinness heighten risk of eating disorders such as anorexia nervosa and bulimia nervosa. Heredity also plays a role.

Discuss social and cultural influences on adolescent sexual attitudes and behavior.

· ● Although sexual attitudes of U.S. adolescents and adults have become more liberal over the past 40 years, North American attitudes toward adolescent sex remain relatively restrictive. Parents and the mass media deliver contradictory messages.

· ● Early, frequent sexual activity is linked to factors associated with economic disadvantage. Adolescent cognitive processes and weak social supports for responsible sexual behavior underlie the failure of many sexually active teenagers to practice contraception consistently.

· Cite factors involved in the development of homosexuality.

· ● Biological factors, including heredity and prenatal hormone levels, play an important role in homosexuality. Lesbian, gay, and bisexual teenagers face special challenges in establishing a positive sexual identity.

Discuss factors related to sexually transmitted disease and teenage pregnancy and parenthood, noting prevention and intervention strategies.

· ● Early sexual activity, combined with inconsistent contraceptive use, results in high rates of sexually transmitted diseases (STDs) among U.S. adolescents.

· ● Life conditions linked to poverty and personal attributes jointly contribute to adolescent childbearing. Teenage parenthood is associated with school dropout, reduced chances of marriage, greater likelihood of divorce, and long-term economic disadvantage.

· ● Effective sex education, access to contraceptives, and programs that build academic and social competence help prevent early pregnancy. Adolescent mothers need school programs that provide job training, instruction in life-management skills, and child care. When teenage fathers stay involved, children develop more favorably.

What personal and social factors are related to adolescent substance use and abuse?

· ● Teenage alcohol and drug use is pervasive in industrialized nations. Drug taking reflects adolescent sensation seeking and drug-dependent cultural contexts. The minority who move to substance abuse tend to start using drugs early and to have serious personal, family, school, and peer problems.

· ● Effective prevention programs work with parents early to reduce family adversity, strengthen parenting skills, and build teenagers’ competence.


Piaget’s Theory: The Formal Operational Stage ( p. 382 )

· What are the major characteristics of formal operational thought?

· ● In Piaget’s formal operational stage, adolescents become capable of hypothetico-deductive reasoning. To solve problems, they start with a hypothesis; deduce logical, testable inferences; and systematically isolate and combine variables to see which inferences are confirmed. image48

· ● Adolescents also develop propositional thought—the ability to evaluate the logic of verbal statements without referring to real-world circumstances.

Discuss follow-up research on formal operational thought and its implications for the accuracy of Piaget’s formal operational stage.

· ● Adolescents, like adults, are most likely to think abstractly and systematically in situations in which they have had extensive guidance and practice in using such reasoning. Individuals in tribal and village societies rarely do well on tasks typically used to assess formal operational reasoning. Learning activities in school provide adolescents with rich opportunities to acquire formal operations.

An Information-Processing View of Adolescent Cognitive Development ( p. 384 )

· How do information-processing researchers account for cognitive changes in adolescence?

· ● Information-processing researchers believe that a variety of specific mechanisms underlie cognitive gains in adolescence: improved attention, inhibition, strategies, knowledge, metacognition, cognitive self-regulation, speed of thinking, and processing capacity.

· ● The ability to coordinate theory with evidence improves as adolescents solve increasingly complex problems and acquire more sophisticated metacognitive understanding.

Consequences of Adolescent Cognitive Changes ( p. 386 )

Describe typical reactions of adolescents that result from their advancing cognition.

· ● As adolescents reflect on their own thoughts, two distorted images of the relation between self and other appear—the imaginary audience and the personal fable. Both result from heightened social sensitivity and gains in perspective taking. image49

· ● Teenagers’ capacity to think about possibilities prompts idealistic visions at odds with reality, and they often become fault-finding critics.

· ● Adolescents are less effective at decision making than adults. They take greater risks in emotionally charged situations, less often weigh alternatives, and more often fall back on intuitive judgments.

Sex Differences in Mental Abilities ( p. 388 )

What factors contribute to sex differences in mental abilities at adolescence?

· ● Girls’ advantage in reading and writing achievement increases, probably due to earlier development of the left hemisphere of the cerebral cortex, more efficient language processing, and greater verbal stimulation. Gender stereotyping of language arts as “feminine” and regimented teaching may weaken boys’ literacy skills.

· ● By early adolescence, when concepts become more abstract and spatial, boys surpass girls in mathematical performance. Overall, the gender difference is small, but it is greater among the most capable. Boys’ superior spatial reasoning enhances their mathematical problem solving. Gender stereotyping of math as “masculine” contributes to boys’ greater self-confidence and interest in pursuing STEM careers.

Learning in School ( p. 391 )

Discuss the impact of school transitions on adolescent adjustment.

· ● School transitions bring larger, more impersonal school environments, in which grades and feelings of competence decline. Girls experience more adjustment difficulties. Teenagers coping with added stressors are at greatest risk for self-esteem and academic problems.

Discuss family, peer, school, and employment influences on academic achievement during adolescence.

· ● Authoritative parenting and parents’ school involvement promote high achievement, Teenagers whose parents value achievement generally choose friends who share those values. Schools can help by promoting a peer culture that values school engagement. image50

· ● Warm, supportive classroom environments that encourage student interaction, and high-level thinking enable adolescents to reach their academic potential.

· ● By high school, separate educational tracks that dovetail with students’ future plans are necessary. However, U.S. high school tracking usually extends the educational inequalities of earlier years.

· ● The more hours students work at a part-time job, the poorer their school attendance, academic performance, and extracurricular participation. But work–study programs that provide academic and vocational learning opportunities predict positive school and work attitudes and better academic achievement.

What factors increase the risk of high school dropout?

· ● Factors contributing to the high U.S. dropout rate include lack of parental support for achievement, a history of poor school performance, large impersonal secondary schools, and unsupportive teachers.

Important Terms and Concepts

adolescence ( p. 361 )

anorexia nervosa ( p. 372 )

body image ( p. 371 )

bulimia nervosa ( p. 373 )

formal operational stage ( p. 382 )

growth spurt ( p. 363 )

hypothetico-deductive reasoning ( p. 382 )

imaginary audience ( p. 386 )

menarche ( p. 365 )

personal fable ( p. 386 )

primary sexual characteristics ( p. 365 )

propositional thought ( p. 383 )

puberty ( p. 361 )

secondary sexual characteristics ( p. 365 )

secular trend ( p. 367 )

spermarche ( p. 366 )

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