1. PHYSICAL DEVELOPMENT IN ADOLESCENCE
Chapter 14
© 2013 The McGraw-Hill Companies, Inc. All rights reserved.

2. Positive and Negative Views of Adolescents
Adolescent thoughts more abstract
G. Stanley Hall: ‘storm-and-stress’ view
Adolescence, like childhood, is interaction of genetic, biological, environmental, and social factors
Daniel Offer
Cross-cultural studies of adolescents
Happy most of the time, have self-control, value work and school, can cope with life
Positive feelings toward their families

3. Positive and Negative Views of Adolescents
Tastes and manners
Look and act different from other generations
Music, hairstyles, clothing
Enthusiasm for new identities
Some rebellion, outrage, hostility
Test boundaries, parental values
Path to adulthood: lengthy negotiations

4. Positive and Negative Views of Adolescents
Damon:
Adolescents taught short-sighted thinking, immediate gratification, etc.
Short-term solutions promote adapting to situation but distract from long-term questions
Parents need to teach children to think long term and about ‘life’

5. Developmental Transitions
Biological changes
Growth spurt and hormonal changes
Sexual maturity and puberty
Brain maturation and altered sleep patterns
Cognitive changes
Increased abstract, idealistic, logical thinking
Increased egocentric perceptions
More responsibility given by parents

6. Developmental Transitions
Socioemotional changes
Increased independence and time spent with peers; more conflict with parents
More mood swings, sexual maturation, and romantic relationships; more intimacy and self-disclosure occurs
Larger, impersonal schools; more pressure to academically achieve

7. Developmental Transitions
Adolescence to adulthood
Emerging adulthood: 18 to 25 years
Identity exploration; love and work
Instability; changes
Self-focused
Feeling in-between
Experiencing the age of possibilities

8. Sexual Maturation, Height, and Weight
Puberty:
Period of rapid physical maturation; hormonal and bodily changes over time
Puberty in Girls
Menarche: Girl’s first menstruation
Irregular cycles and ovulation in first year
Growth spurt 2 years earlier than boys
Breast growth, hips widen, pubic hair appears
Armpit hair appears later

9. Sexual Maturation, Height, and Weight
Puberty in males
Spermarche: First ejaculation/Viable sperm
Increased penis and testicle size
Pubic hair growth, facial hair
Voice changes/deepens
Hair growth in armpits
Overall
Girls outweigh boys until about age 14
Males grow taller, faster than girls

10. Hormonal Changes
Powerful chemical substances secreted by endocrine glands
Interaction of hypothalamus, pituitary gland, sex glands (gonads in males; ovaries in females)
Hypothalamus: monitors eating, drinking, and sex
Pituitary gland: controls growth, regulates other glands

11. Hormonal Changes Gonadotropins: Stimulate ovaries/testes Timing
Testosterone associated with male development of genitals, increased height, and voice change
Estradiol associated with female breast development, uterine, and skeletal development
Timing
U.S. children mature faster than Europeans
Age of maturity has decreased in last 100 years

12. Psychological Dimensions of Puberty
Body image
Adolescents preoccupied with physical looks
More acute in early adolescence
Differences
Girls more negative than boys about image; dissatisfaction increases with age in puberty
Early and late maturation seen as ‘being different from peers’
Early maturing girls: shorter, stockier

13. The Brain Corpus callosum Prefrontal cortex Amygdala
Fibers connect hemispheres of the brain
Prefrontal cortex
Reasoning; finishes maturing in adult years
Amygdala
Seat of emotions; matures early but adolescent does not have total self-control ability
Issue: Do biological brain changes or experiences stimulate emotional changes?

14. Developing A Sexual Identity
Adolescence is time of:
Ambivalence; sex used in movies/videos/TV shows/music
Frequent viewing tied to casual sex attitudes
Mastering sexual feelings and forming sense of sexual identity is lengthy, multifaceted
Gay and lesbian youth have diverse patterns of initial attraction, often bisexual

15. Timing and Trends Timing of sexual initiation varies by:
Country, gender, other socioeconomic factors
In U.S.
African American males and inner-city adolescents are most sexually active
Asian American adolescents have most restrictive sexual timetable

16. Timing and Trends Currently in U.S.
Over 60% of 12th graders; over 30% of 9th graders have had sex
Dramatic increase in oral sex during adolescence
55% of male adolescents, aged 15 to 19
54% of females, aged 15 to 19
Affected by heavy drinking, having sexually active friends, and approving friends

17. Sexual Risk Taking in Adolescence
Sexually active teens under 16
Ineffective users of contraceptives
At risk for teen pregnancy and STDs
Linked to alcohol and drug use, low academic achievement, and earlier age for sexual initiation
Linked to early adolescent sex problems
SES, family/parenting and peer factors
Low self-esteem, extensive TV watching

18. Sexual Risk Taking in Adolescence
Cognitive factors in sexual risk taking
Attention problems
Multiple school problems, antisocial behavior, substance use in middle school
Self-regulation (emotions and behaviors)
Contraceptive use
Adolescents: substantial increase in use
Many still do not use contraceptives
Older teens more likely to reduce risks

19. Sexual Risk Taking in Adolescence
Sexually transmitted infections
Contracted through bodily fluid contact
About 25% of ‘active’ teens infected each year
Bacterial infections (syphilis, chlamydia)
Viral infections (genital herpes, AIDS, etc.)
AIDS destroys body’s immune system
15% in U.S. were 13 to 24 years of age
Devastating sub-Saharan African countries
Some infections from needles of drug users

20. Sexual Risk Taking in Adolescence
Adolescent pregnancy
U.S. rates declining; still one of highest in industrialized world
Reasons for decreasing:
Fear of STIs, especially AIDS
School, community awareness classes
Greater hope for future
Latina teens at most risk of teen pregnancy

22. Sexual Risk Taking in Adolescence
Cross-cultural comparisons of adolescent pregnancy
Three reasons why U.S. rates so high
Childbearing viewed as adult activity
Other countries encourage teens to wait, but teen sexual expression more accepted
Access to family planning services
U.S. expectations and attitudes more lax, yet access to planning services more restricted

23. Sexual Risk Taking in Adolescence
Adolescent pregnancy has risks
Low-birthweight infants more likely; linked to infant mortality, neurological and health issues
Young mothers quit school, have less earning power, fewer economic resources available
Low SES teens have higher risk
More likely female child born to teen mother will perpetuate intergenerational cycle
Teen moms may do low parental monitoring

24. Adolescent Health To improve
Increase adolescents’ health-enhancing behaviors (eating, sleep, seat belts, etc.)
Reduce adolescents’ health-compromising behaviors (sex abuse, violence, etc.)
Adoption of correct behaviors relevant to health
Nutrition and exercise are important
Obesity linked to health problems

25. Adolescent Health
Being overweight related to low self-esteem, depression, problems with peers
U.S. youth compared to most in world
Eat more junk food; less fruits and vegetables
Boys more active than girls
Exercise less and more inactive
Ethnic differences: white boys exercise most; African American girls exercise least
Exercise buffers against stress

26. Adolescent Health Inadequate sleep causes problems
Irritability, depression, drinking caffeinated drinks
Linked to lower exercise levels, less effective stress management, unhealthy diet
Need at least 9 or more hours sleep per night
Older teens stay up later, get less sleep
Shortfall deficits usually made up on weekends
Research: start school later, melatonin secreted later in morning in teens

27. Leading Causes of Death
Accidents: over 50% of deaths ages 15–24
Most due to motor vehicles and risky behaviors like speeding, use of drugs or alcohol
Homicide: second leading cause, especially among African American males
Suicide rates continue to rise since 1950s

28. Substance Use and Abuse
U. of Michigan annual research
8th, 10th, 12th graders
Decline in illicit drug use since 1990s; still one of highest in industrialized nations
Sizeable decline in alcohol use; binge drinking
Cigarette use still declining since 1996; nicotine is active drug that harms
Now: alarming use of prescription painkillers
Parents were main source of supplies

29. Substance Use and Abuse
Roles of development, education, parents, and peers
The earlier one begins, the higher the risk of long-term addiction
Educational success: strong buffer against use
Social support of parents and peers can be positive or negative
Consistent routines and contact are key

30. Eating Problems and Disorders
Increasingly common among adolescents
Body image may be source of dissatisfaction
Parent-child relationships linked to eating patterns and exercise
Age of onset of sexual activity and type of relationship affects healthy eating patterns
Role models and media have effect
Intervention approaches
Clinical, behavioral therapy, school-based

31. Eating Problems and Disorders
Anorexia nervosa
Eating disorder, relentless desire to be thin through starvation; serious, can lead to death
Main characteristics
Weighing less than 85% of normal weight
Having intense fear of gaining weight
Having distorted image of one’s body shape

32. Eating Problems and Disorders
Bulimia nervosa
Eating disorder with binge-and-purge pattern of eating, use of laxatives
Eating Disorders
Begins in teen years
Mostly white, female, well-to-do families
Unable to meet high expectations, competition
Influenced by fashion industry and media