Physical & Cognitive Development in Adolescence

Chapter 8

Pubertal Changes

Physical growth (girls begin 11, boys 13) Weight increase (20-25 lbs) Bones lengthen

Head, hands, feet first

Muscle density increases (boys > girls) Body fat increases (girls > boys) Heart, lung capacity increases (boys > girls)

Pubertal Changes

Sexual maturation Primary sexual characteristics

Reproductive organs (ovaries, testes, etc.)

Secondary sexual characteristicsBreasts, pelvis, facial hair, broadening shoulders,

voice changeMenarche (menstruation) ~13Spermarche (1st ejaculation - but few sperm) ~13

Mechanisms of Maturation

Hypothalamus (‘master gland’) Hormones->pituitary gland->growth hormone Pituitary gland signals other organs to release

hormonesAdrenal gland -> androgen (hair)Ovaries -> estrogen (breasts, genitals, body fat)Testes -> testosterone (genitals, muscle mass)

Mechanisms of Maturation

Timing regulated in part by genes Mother’s age at menarche predicts daughter’s

Other influences Nutrition Health

Better = sooner puberty onsetCultural & historical differences linked to health

Psychological Impacts

Body image Girls less pleased with changes Boys happy with changes later

Affect: Adolescents are ‘mood’ Not hormones Changing activities/social circumstances

Psychological Impacts

Maturation rates Early maturing boys confident, independent,

popular (v. late maturing boys)Problems with late maturing fades by adulthood

Early maturing girlsInsecure, less popular, depressed, have conduct

disorderLasting effects (e.g., pregnancy)s

Health

Obesity 2001 Surgeon General declared childhood

obesity an epidemicObese children doubled, obese adolescents

tripled during past 25 years (1/7 overweight)

Unpopular, low self-esteem Heightened risk for health problems

Health

Obesity risk factors Heredity plays a role (passive & active)

Overweight parents tend to have overweight kids• Metabolic rate inherited?

Genes -> activity level -> weight

Media images of fatty foods Parents may emphasize external eating cues

Health

Weight loss programs do work Change eating, behavior habits Monitor eating, exercise Set realistic goals

Health

Anorexia nervosa Persistent refusal to eat and irrational fear of

being overweight Distorted body image

Damages heart, without treatment 15% die

Bulimia nervosa Cycles of binge eating/vomiting

Health

Eating disorders Females > males More common in industrialized cultures Roots in female body image

Rates track changes in ideal female body

Risk factors/Causes Autocratic parents, culture, genes

Health

Threats to adolescent well being Motor vehicle accidents Firearms Accidents (due to risky behavior)

Decision making: emphasize social consequences more than health factors

Cultural differencesMore MVA for European, more firearms for African

Information Processing

Working memory, processing speed Both increase during adolescence ~adults by mid-adolescence

Content knowledge Increases dramatically in areas of interest

Metacognitive skills Improved ability to choose appropriate

strategies for a task and monitor progress

Moral Thinking

Kohlberg: 3 levels of moral reasoning Preconventional (2 stages): punish/rewards

External factors/obedience orientationInstrumental orientation (exchange nice beh for…)

Conventional (2 stages): social normsFollows societal normsFollow rule to maintain social order (social system)

Postconvetional (2 stages): moral codesValid social contractUniversal ethics: abstract morality

Moral Thinking

Research generally supports Kohlberg During adolescence stage 3-4 reasoning

increases Longitudinal studies indicate no regression Studies link moral reasoning & moral behavior

Moral Thinking

Kohlberg’s theory is a Western view US - justice orientation key Hindus in India - care orientation key

Promote moral reasoning Modeling Discussion w/ more developed moral thinkers