Adolescence

1. Adolescence • Heralded by two significant changes in development: • Growth spurt (change in size and shape) • Puberty (sexual maturity)

2. Growth spurt • A rapid acceleration of height and weight • Marks the beginning of puberty • Girls start growth spurt around age 10, and it peaks around age 12 • Boys start growth spurt around age 10-13, it peaks at 14, and then slows. • Body assumes a more adult look during growth spurt. • Facial features lose childish cuteness, and lips grow fuller.

3. Sexual maturation in girls • Girls usually start it by age 11 (trend is even earlier today) • Begins with development of breasts and pubic hair • Vagina becomes larger, and uterine muscles become stronger in preparation for pregnancy

4. Menarche • Menarche (first menstrual period) occurs at age 12-13 on average in Western countries. • Body weight of 106 +/- 3 lbs triggers menarche and the end of the growth spurt. • Fat must make up 17% of the girl’s weight to begin and maintain menstruation. • For 12-18 months after menarche, girls are usually functionally sterile because the menstrual cycle often takes place without an ovum being released (i.e., in early menstruation, you can have a period without having ovulated first).

5. Reactions to menarche • A couple of generations ago, it was considered traumatic—in the 1950s, about 50% of girls had very little forewarning or preparation and reacted with shock. • Today, most girls react with surprise due to the sudden onset of the event. • Reactions are mixed—few are elated but few are devastated. • Girls whose fathers are aware of the fact that they’ve started their periods adjust especially well.

6. Sexual maturation in boys • Starting around age 11 or 11 ½, testes and scrotum enlarge. • About six months to a year later, the penis gets larger, and the growth spurt occurs. • Around age 14, males are capable of fathering children. • Have first ejaculation of viable sperm around this age (14). It’s called spermarche.

7. Boys’ reaction to spermarche • Boys’ responses are mixed. • Almost all boys know about ejaculation ahead of time, but many say that no one spoke to them before or during puberty about physical changes. Usually acquire knowledge on their own (reading or talking to others) • Boys usually say their first ejaculation occurred earlier than expected and that they were unprepared for it. • Boys who felt better prepared react more positively.

8. Sharing the news with others • Almost all girls tell a friend that they have begun menstruating. • Almost no boys tell anyone about spermarche. • Boys get much less social support than girls about the physical changes of puberty.

9. Concern with appearance: Girls • Girls are especially concerned about their appearance, and bodily changes congruent with femininity are usually welcomed. • When breasts appear early, girls think they’re going to be more successful in their careers and feel better about themselves. • Girls are concerned about being too tall or too fat, and eating disorders may develop. • Girls worry about size of their ears, nose, and hips, and about the texture of their hair. Self-concept depends on how attractive they feel.

10. Boys’ concern with appearance • Boys are very concerned about body image as well. • Want to be tall, muscular, and hairy • Welcome weight gain and are much less likely than girls to view themselves as overweight

11. Early vs. late development: Boys • Boys who mature early have many advantages • Jones & Bayley (1950): longitudinal study showed that late maturers were eager, socially immature, anxious, and rated as more unattractive and less masculine by peers and teachers. They felt unsure in social situations and had lower educational aspirations. • Early maturers were more poised, confident, & overrepresented in sports and student offices. Less likely to lose control or use drugs.

12. Persistence of effects of early vs. late maturity • Follow-up study (30 years after original longitudinal study) showed that • Many differences had diminished somewhat, but later maturers were still less popular and less confident. • Later maturers were less “cognitively rigid”—less authoritarian, more creative,a nd more tolerant of ambiguous circumstances. • Overall, late maturers did not fare as well as early maturers did.

13. Why do early-maturing boys do better? • Early maturers are more athletic, and with athleticism comes adoration, which helps their self-esteem. • Parents hold more educational aspirations for early-maturing sons. • Get more privileges and fewer curfews, which is thought to promote more poise and self-confidence.

14. Early-maturing girls • Less outgoing and less popular, at least at first; they are ostracized by less-developed peers. • Often seek older companions, who may steer them away from academics and into dating, smoking, etc. • Parents generally restrict early-maturing girls more, which may lead to conflicts and surly attitudes.

15. Specific findings about early-maturing girls • More anxious, lacking in self-confidence, and unpopular • Hold few leadership positions • More involved in deviant behavior (getting drunk, having sex early, etc.) • Didn’t do as well in school. • They do a little better in middle school, where their mature bodies lead to popularity with both boys and girls. • Some evidence shows they’re more self-directed and better able to cope with stress later.

16. Late-maturing girls • Fare much better than early-maturing girls do • Regarded by peers as physically attractive, lively, sociable, and leaders at school • Parents don’t come down as hard on late-maturing girls.

17. Sexual activity in teenagers • Hormonal changes of puberty (particularly androgen production in both males and females) lead to an increased sex drive. • Parents typically give children very little information about sex and don’t tolerate sexuality (masturbation, etc.) • The more warm and open parents are about sex with their children/adolescents, the LESS sexual risk-taking they engage in.

18. Premarital sex • After a generation of more liberal attitudes about sex, the pendulum has swung back to the conservative side today. Largely due to the impact of AIDS. • Rate of premarital sex in US has declined since 1990. • Still, 70% of Americans have had sex by age 18-19. • Almost 40% are sexually active by age 15. • Boys usually lose virginity earlier than girls do; average age is 17 for first intercourse.

19. Characteristics of teens who have early sex • Usually went through puberty early • Parents likely divorced, may be remarried • Little or no religious involvement in the family • Weak parental monitoring and lack of parent-child communication • Sexually active friends and siblings • Poorer school performance and lower educational aspirations • Tendency to engage in “rebellious” acts such as drugs, drinking, and delinquency. • Strongly associated with low SES

20. Fathers’ role in daughter’s sexual behavior • Early and prolonged father absence predicts higher rates of intercourse in girls. • Could be that girls whose fathers were absent view male commitment as uncertain, so they enter into casual sexual relationships more readily. • Girls whose fathers were present may reject casual sex in order to find a committed male “just like Dad.”

21. Contraceptive use • Adolescent contraceptive use has increased in recent years, but 27% of sexually active US teens don’t use it consistently. • Adolescents aren’t cognitively mature enough to accurately see the dangers of unintended pregnancy and apply it to their own situation. • Parents who talk openly about sex and contraception have children who use birth control more consistently.

22. Adolescent pregnancy • About 900,000 teenage girls in US become pregnant every year; 30,000 are younger than age 15 • 40% of teen pregnancies in US end in abortion. • Three factors predict teenage pregnancy: • Lack of effective sex education • Scarcity of convenient, low-cost contraception • Impoverished backgrounds, which leads to risk-taking behaviors.

23. Teenage parenthood • Being a parent is especially challenging for adolescents, who lack maturity and a clear direction for their own lives. • Teen parents are many more times likely to be poor than those whose postpone childbearing. • Backgrounds include low parental warmth & involvement, domestic violence and child abuse, repeated parental divorce & remarriage, and low SES neighborhoods where teen pregnancy is common and accepted.

24. How life worsens for the teen parent • Educational attainment: Giving birth before age 18 reduces likelihood of finishing high school • Marital patterns: Teen motherhood reduces the chances of marriage, and when they do marry, they’re more likely to get divorced. • Economic circumstances: Many teen mothers are on welfare and find themselves restricted to unsatisfying, low-paying jobs. Teen fathers usually earn too little to provide children with basic necessities.

25. Ethnic differences in teen pregnancy • High percentage of out-of-wedlock births are to low-income minority teenagers: African-Americans, Native-Americans, and Hispanics. • An estimated 50% of teen fathers have been in trouble with the law enough and are imprisoned.

26. Other consequences of teen pregnancy • Get less prenatal care and are more likely to smoke, drink, and use drugs/alcohol, so babies’ birth weight is lower…more birth complications likely. • Adolescent moms know very little about child development, have unrealistically high expectations of infants, perceive their babies are more difficult, and interact more poorly with them.

27. The children of teen moms • Tend to score low on achievement tests • Achieve poorly in school • Engage in disruptive social behavior • The cycle of adolescent pregnancy is thus more likely to be repeated in this next generation.

28. Sexual orientation • About 2 to 3% of young people identify themselves as gay, lesbian, or bisexual. • Heredity is strongly implicated in homosexuality. • Identical twins of both sexes are more likely to be homosexual than fraternal twins are. • Male homosexuality is more common on the maternal than on the paternal side of families; may be an X-linked trait. • 82% of male homosexuals have an identical segment of DNA on the X chromosome.

29. Homosexuality & heredity, cont. • Certain genes may affect the level or impact of prenatal sex hormones, which modify brain structures in ways that produce homosexuality. • Girls who are exposed prenatally to very high levels of androgens OR estrogens (either from a genetic defect or certain drugs given to the mother to prevent miscarriage) are more likely to become homosexual or bisexual. • Gay men tend to be later in birth order and have a higher-than-average number of older brothers (moms may develop antibodies to androgens)