Chapter 14 Introduction

Adolescence: Biosocial Development

  • Puberty Begins
    • Unseen Beginnings
    • OPPOSING PERSPECTIVES: Algebra at 7 A.M.? Get Real
    • Age and Puberty
    • A VIEW FROM SCIENCE: Stress and Puberty
    • Too Early, Too Late
  • Growth and Nutrition
    • Growing Bigger and Stronger
    • Diet Deficiencies
    • Eating Disorders
  • Brain Development
    • A Need for Caution
    • A CASE TO STUDY: “What Were You Thinking?
    • Benefits of Adolescent Brain Development
  • Sexual Maturation
    • Sexual Characteristics
    • Sexual Activity
    • Problems with Adolescent Sex

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WHAT WILL YOU KNOW?

  1. Since puberty begins anytime from age 8 to 14, how can onset be predicted for a particular child?

    If a child’s genes, gender, body fat, and stress levels are known, it is possible to predict timing of puberty. Genetic differences among ethnic groups lead African Americans to reach puberty earliest and Chinese Americans to reach puberty latest. Northern European girls reach menarche earlier than southern European girls. Girls reach puberty on average two years earlier than boys. Heavier girls reach puberty years earlier than malnourished girls do; 100 pounds appears to be the critical minimum weight for menarche to occur. Heavier boys reach puberty later than boys who are closer to their ideal weight. Body fat produces leptin, which is necessary for the onset of puberty. Stress hastens the onset of puberty.

  2. Why do some teenagers starve themselves and others overeat?

    Many teenagers are unhappy with their bodies, in part because few look like the bodies portrayed in the media. Dissatisfaction with body image can be dangerous, leading to eating disorders such as anorexia and binge eating. Anorexia is particularly common among high-achieving, upper-class young women. Adolescents are at risk for binge eating because they so often try new diets, go without food for 24 hours, take diet drugs, and eat odd diets. When their self-control is taxed, a binge is likely to occur.

  3. Since adolescent sexual impulses are powerful and inevitable, why is there so much variation in rates of teen pregnancy and STIs?

    A universal experience (rising hormones) that produces another universal experience (growth of primary and secondary sex characteristics) is influenced by cohort, gender, and culture. One of the most powerful influences on adolescent sexual activity is close friends.

I overheard a conversation among three teenagers, including my daughter Rachel, all of them past their awkward years and now becoming beautiful. They were discussing the imperfections of their bodies. One spoke of her fat stomach (what stomach? I could not see it), another of her long neck (hidden by her silky, shoulder-length hair). Rachel complained not only about a bent pinky finger but also about her feet!

The reality that children grow into men and women is no shock to any adult. But for teenagers, heightened self-awareness often triggers surprise or even horror, joy, and despair at the specifics of their development. Like these three, adolescents pay attention to details of their growth.

This chapter describes the biosocial specifics of growing bodies and emerging sexuality. It all begins with hormones, but other invisible changes may be even more potent—such as the timing of neurological maturation that does not yet allow adolescents like these three to realize that minor imperfections are insignificant.