Share Your Thoughts Week 4

02 Sep Share Your Thoughts Week 4

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

·   PHYSICAL DEVELOPMENT

·   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

·   COGNITIVE DEVELOPMENT

·   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.

PHYSICAL DEVELOPMENT

 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.

 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.