Chapter 9

1. Chapter 9 Physical and Cognitive Development in Adolescence PowerPoints developed by Nicholas Greco IV, College of Lake County, Grayslake, IL (c) 2012 The McGraw-Hill Companies, Inc.

2. The Nature of Adolescence • Adolescence is a transitional period with continuity and discontinuity with childhood • Not just a time of rebellion, crisis, pathology, and deviance • More accurately, it is of a time of evaluation, decision making, commitment, finding a place in the world • Ethnic, cultural, gender, socioeconomic, age, and lifestyle differences influence the actual life trajectory of every adolescent (c) 2012 The McGraw-Hill Companies, Inc.

3. The Nature of Adolescence • Adolescents are exposed to complex options through the media • They face the temptations of drug use and sexual activity • Too many adolescents are not provided with adequate opportunities and support to become competent adults (c) 2012 The McGraw-Hill Companies, Inc.

4. Puberty • Puberty is not the same as adolescence • most important marker of the beginning of adolescence • puberty ends long before adolescence does • Puberty -- period of rapid physical maturation involving hormonal and bodily changes • Puberty is not a single, sudden event • the most noticeable changes are signs of sexual maturation and increases in height and weight (c) 2012 The McGraw-Hill Companies, Inc.

5. Order of Male Pubertal Changes • Increase in penis and testicle size • Appearance of straight pubic hair • Minor voice change • First ejaculation (which usually occurs through masturbation or a wet dream) • Appearance of kinky pubic hair • Onset of maximum growth in height and weight • Growth of hair in armpits • More detectable voice changes • Growth of facial hair (c) 2012 The McGraw-Hill Companies, Inc.

6. Order of Physical Changes in Females • Breasts enlarge • Pubic hair appears • Hair appears in the armpits • Height increases and hips become wider than shoulders • Menarche, first menstruation, irregular and anovulatory • Voice changes not comparable to males • By the end, breasts become more fully rounded (c) 2012 The McGraw-Hill Companies, Inc.

7. Weight and Height and the Growth Spurt • Girls tend to outweigh boys early in adolescence • At the beginning of adolescence, girls tend to be as tall as or taller than boys of their age • The mean age at the beginning of the growth spurt in girls is 9 and for boys, the mean age is 11 (c) 2012 The McGraw-Hill Companies, Inc.

8. (c) 2012 The McGraw-Hill Companies, Inc.

9. Hormonal Changes • Hormones-- powerful chemical substances secreted by the endocrine glands and carried through the body by the bloodstream • Puberty is an interaction of the hypothalamus, the pituitary gland, and the gonads • Gonads -- the testes and ovaries -- are particularly important (c) 2012 The McGraw-Hill Companies, Inc.

10. Hormones • Testosterone -- hormone associated in boys with the development of genitals, an increase in height, and a change in voice • Estradiol is a type of estrogen • in girls it is associated with breast, uterine, and skeletal development • Testosterone and estradiol are present in the hormonal makeup of both boys and girls • The hormone-behavior link is complex (c) 2012 The McGraw-Hill Companies, Inc.

11. Timing and Variations in Puberty • The average age of menarche has declined significantly since the mid-19th century • Basic genetic program for puberty is wired into the species • nutrition, health, and other environmental factors also affect puberty’s timing and makeup • Average age for the pubertal sequence to begin is between 10 to 13.5 for boys and 9 to 15 for girls (c) 2012 The McGraw-Hill Companies, Inc.

12. Body Image • Adolescents are preoccupied with their bodies and develop images of what their bodies are like • Girls are less happy with their bodies and have more negative body images than boys throughout puberty • Boys become more satisfied as they move through puberty, probably because their muscle mass increases (Bearman & others, 2006) (c) 2012 The McGraw-Hill Companies, Inc.

13. Early and Late Maturation • Adolescents who mature earlier or later than their peers perceive themselves differently • Early maturation in girls increases vulnerability to problems • more likely to smoke, drink, be depressed, have an eating disorder, struggle for earlier independence from their parents, have older friends, date, and earlier sexual experiences (c) 2012 The McGraw-Hill Companies, Inc.

14. Brain Development • Adolescents’ brains undergo significant structural changes • corpus callosum -- thickens and this improves ability to process information • prefrontal cortex doesn’t finish maturing until 18 to 25 years of age or later • amygdala -- the seat of emotions such as anger -- matures earlier than the prefrontal cortex (c) 2012 The McGraw-Hill Companies, Inc.

15. Insert Figure 9.2 (c) 2012 The McGraw-Hill Companies, Inc.

16. Adolescent Sexuality • A time of sexual curiosity, exploration and experimentation, of sexual fantasies and realities, of incorporating sexuality into one’s identity (c) 2012 The McGraw-Hill Companies, Inc.

17. Developing a Sexual Identity • Involves learning to manage sexual feelings (such as sexual arousal and attraction) and developing new forms of intimacy • Learning skills to regulate sexual behavior to avoid undesirable consequences • Sexual identity involves activities, interests, styles of behavior, and an indication of sexual orientation -- whether an individual has same-sex or other-sex attractions (Buzwell & Rosenthal, 1996) (c) 2012 The McGraw-Hill Companies, Inc.

18. The Timing of Adolescent Sexual Behaviors • The timing of sexual initiation varies by country, gender, or socioeconomic characteristics • Many early adolescents are not emotionally prepared to handle sexual experiences • Early sexual activity is linked with risky behaviors such as drug use, delinquency, and school-related problems • Low parental monitoring was linked with early initiation of sexual activity (c) 2012 The McGraw-Hill Companies, Inc.

19. Contraceptive Use • Two kinds of risks accompany sexual activity: • Unintended, unwanted pregnancy • Sexually transmitted infections • Both can be reduced significantly with contraception use • Many sexually active adolescents still do not use contraceptives, or they use them inconsistently • Younger adolescents are less likely to take contraceptive precautions (c) 2012 The McGraw-Hill Companies, Inc.

20. Sexually Transmitted Infections   • Sexually transmitted infections (STIs) -- infections contracted primarily through sexual contact, including oral-genital and anal-genital contact • annually, more than 3 million American adolescents • about one-fourth of those who are sexually experienced (Centers for Disease Control and Prevention, 2008) (c) 2012 The McGraw-Hill Companies, Inc.

21. Adolescent Pregnancy • United States has one of the highest adolescent pregnancy and childbearing rates in the industrialized world; however, recent declines are noted • Reasons for these recent declines include increased contraceptive use and fear of sexually transmitted infections such as AIDS (c) 2012 The McGraw-Hill Companies, Inc.

22. Birth Rates for U.S. Adolescents from 1980 to 2008 • INSERT FIGURE 9.3 HERE (c) 2012 The McGraw-Hill Companies, Inc.

23. Risks of Becoming Pregnant as an Adolescent • Health risks for both the baby and the mother • Infants are more likely to have low birth weight • Infants have more neurological problems and childhood illness • Adolescent mothers often drop out of school • Even if they resume their education, they generally never catch up economically (c) 2012 The McGraw-Hill Companies, Inc.

24. Characteristics • Adolescent mothers are more likely to come from low-SES backgrounds • Many were not good students before they became pregnant • Some adolescent mothers do well in school and have positive outcomes • All adolescents can benefit from age-appropriate family-life education (c) 2012 The McGraw-Hill Companies, Inc.

25. Issues in Adolescent Health • Many of the behaviors that are linked to poor health habits and early death in adults begin during adolescence • Early formation of healthy behavior patterns, such as regular exercise and a preference for foods low in fat and cholesterol • has immediate health benefits • helps in adulthood to delay or prevent disability and mortality (c) 2012 The McGraw-Hill Companies, Inc.

26. Nutrition and Exercise • The percentage of overweight teens in the United States increased from the early 1990s through 2004 • Compared to adolescents in 28 countries, U.S. and British adolescents ate more fried food and less fruits and vegetables • U.S. boys and girls become less active as they reach and progress through adolescence (c) 2012 The McGraw-Hill Companies, Inc.

27. Nutrition and Exercise • Adolescent boys are more likely to engage in moderate to vigorous exercise than were girls • Exercise is linked to a number of positive physical outcomes • Lower weight, reduced triglyceride levels, lower blood pressure, a lower incidence of type II diabetes, lower drug use (c) 2012 The McGraw-Hill Companies, Inc.

28. Percentage of U.S. High School Students Who Ate Fruits and Vegetables Five or More Times a Day • INSERT FIGURE 9.4 HERE (c) 2012 The McGraw-Hill Companies, Inc.

29. Sleep Patterns • Only 45 percent of adolescents studied got inadequate sleep on school nights (fewer than 8 hours) • inadequate sleep resulted in feeling more tired or sleepy, cranky and irritable, falling asleep in school, being in a depressed mood, and drinking caffeinated beverages • adolescents’ biological clocks undergo a shift as they get older; this seems related to a delay in the nightly release of the sleep-inducing hormone melatonin (National Sleep Foundation, 2006) (c) 2012 The McGraw-Hill Companies, Inc.

30. Leading Causes of Death in Adolescence   • The three leading causes of death in adolescence are accidents, homicide, and suicide • More than half of deaths for ages 15 to 24 are due to unintentional injuries; three-fourths involve motor vehicles • Homicide is the second-leading cause of death, especially among African-American males • The adolescent suicide rate has tripled since the 1950s (c) 2012 The McGraw-Hill Companies, Inc.

31. Substance Use and Abuse • Proportions of U.S. students who used any illicit drug declined in the late 1990s and first years of the 21st century • The United States still has one of the highest rates of adolescent drug use of any industrialized nation • Early onset of drinking linked to increased risk of heavy drinking in middle age • Parents play a role in preventing drug abuse • Peers also influence whether adolescents become substance abusers (Johnston & others, 2010) (c) 2012 The McGraw-Hill Companies, Inc.

32. Trends in Drug Use by U.S. 8th, 10th, and 12th Graders • INSERT FIGURE 9.6 HERE (c) 2012 The McGraw-Hill Companies, Inc.

33. Anorexia Nervosa • Anorexia nervosa -- eating disorder that involves the relentless pursuit of thinness through starvation • Three main characteristics of anorexia nervosa are: • weighing less than 85 percent of what is considered normal for a person’s age and height • having an intense fear of gaining weight • having a distorted image of one’s body shape (c) 2012 The McGraw-Hill Companies, Inc.

34. Bulimia Nervosa   • Bulimia nervosa -- eating disorder in which the individual consistently follows a binge-and-purge pattern • Bulimics go on an eating binge and then purge by self-inducing vomiting or using laxatives • Bulimics are preoccupied with food, have a strong fear of becoming overweight, and are depressed or anxious (c) 2012 The McGraw-Hill Companies, Inc.

35. The Formal Operational Stage • According to Piaget, the fourth and final stage of cognitive development, the formal operational stage, begins in adolescence • Formal operational thought is more abstract and logical; full of idealism and possibilities • Hypothetical-deductive reasoning involves creating a hypothesis and deducing its implications (c) 2012 The McGraw-Hill Companies, Inc.

36. Adolescent Egocentrism • Adolescent egocentrism is the heightened self-consciousness of adolescents • David Elkind (1976) cited two key components: • imaginary audience • personal fable • Adolescents also often show a sense of invincibility or invulnerability (c) 2012 The McGraw-Hill Companies, Inc.

37. Information Processing • Executive functioning involves higher-order cognitive activities such as reasoning, making decisions, monitoring thinking critically, and monitoring one’s cognitive progress • Improvements in executive functioning permit: • more effective learning • making decisions and engaging in critical thinking (c) 2012 The McGraw-Hill Companies, Inc.

38. Decision Making and Critical Thinking • Young adolescents are more likely to generate different options, examine a situation from a variety of perspectives, anticipate the consequences of decisions, and consider the credibility of sources • The social context plays a role in adolescent decision making • Cognitive changes that allow for improved critical thinking are: • Increased speed, automaticity, and capacity of information processing • More benefits of content knowledge • Increased ability to construct new combinations of knowledge • Greater range and more spontaneous use of strategies or procedures for applying or obtaining knowledge (c) 2012 The McGraw-Hill Companies, Inc.

39. School Issues • Top-dog phenomenon -- moving from being the oldest, biggest, and most powerful to being the youngest, smallest, and least powerful students • Consequence of moving from middle to high school • U.S. high school dropout rates have declined • Service learning-- form of education that promotes social responsibility and service to the community (c) 2012 The McGraw-Hill Companies, Inc.

40. Trends in High School Dropout Rates • INSERT FIGURE 9.7 HERE (c) 2012 The McGraw-Hill Companies, Inc.