Chapters 11 & 12

1. Chapters 11 & 12 Adolescence Psyc311 Developmental Dr. Wright

2. Announcements • Volunteer Projects • Please let me know by 03/16! • Other Extra Credit • Film option (5 pts/film) • Library media collection • Write-up film summary (1 pg) • Chapter summaries (5 pts/section) • Article write-ups (2.5 pts/article)

3. Peer review round of proposals • Due the TH after spring break • MIDSEMESTER CLASS EVAL • I’ll be sending out a link over spring break. • PLEASE click on the link and fill this out

4. Definition of Puberty • Pubertas – Latin word for “adult” • Narrow definition: The process by which an individual becomes capable of reproduction. • The activation of the HPG/HPA axis • Broad definition: The physical, psychological, and cultural changes that occur as the growing child transitions into adulthood.

5. Time Periods of Adolescence • Early adolescence – 10 to 13 years old • Continues to be pushed earlier • Middle adolescence – 14 to 17 years old • Late adolescence (early adulthood) – 18 to 22 years old • Continues to be pushed later?

6. physical changes… • Primary sex characteristics • The body organs and reproductive structures and functions that differ between women and men. • Gonads (testes and ovaries) • Secondary sex characteristics • Characteristics of the body that are caused by hormones, develop during puberty, and last through adult life. • Changes in genitals/breasts/voice • Pubic/body/facial hair

7. Tanner Stages • Sexual maturation in girls • Growth of breasts/pubic hair • Body growth • Menarche • Underarm hair/oil & sweat glands • Age of onset: 7 – 13 years

9. Tanner Stages • Sexual maturation in boys • Growth of testes/pubic hair • Body growth • Growth of penis/change of voice • Facial and underarm hair/oil & sweat glands • Age of onset: 9.5 – 13.5 years

11. Rapid acceleration of physical growth • Adolescent growth spurt • 3.5 (girls) to 4.0 (boys) inches/year • ½ adult weight gained during adolescence • Changes in body composition • 3:1 muscle to body fat ratio for boys • 5:4 for girls • Emergence of sex differences in physical performance • Changes in circulatory and respiratory systems • Increase in size/capacity of heart and lungs

14. Two Roles of Hormones • Organizational role (life-long): • Modification of the organism early in life • primarily influencing its anatomy • Organization/structure of CNS • “Feminine” vs. “masculan-ized” brain • Activational role (specific to puberty): • Structural “remodeling” of brain • Increase in salience of sexual stimuli, sexual motivation • Development of secondary sex characteristics

15. Hormone Regulatory System • Endocrine system • HPA axis • Hypothalamus  Pituitary gland  Adrenals • Corticosteroids • Regulates body’s response to stress • HPG axis • Hypothalamus  Pituitary gland  Gonads (Testes/Ovaries) • Sex Hormones (Androgens/Estrogens) • Regulates sexual maturation

17. The biological changes of puberty can affect the adolescent’s behavior in at least three ways

20. impacts of puberty • Self-esteem • Body image • Moods • Fluctuation of moods • Due to hormones or environment? • “Storm and stress”: myth or fact? • Sleep patterns • Delayed phase preference • 9 hours: 1 am to 10 am • Family relations • Transformation of parent-child bond • Peer relations • Transformation of friendships, romantic relationships

21. Timing - individual Factors • Genetic factors • Timing and tempo • Environmental factors • Nutrition • Body weight • Health care • Exposure to hormones/chemicals • Family conflict • Stepfathers

22. Timing - group Factors • Comparisons across socioeconomic groups • Impact of poverty • Dietary intake, health care, exposure to disease • Comparisons across countries • Comparisons across time periods • Secular trend

23. Early Maturation • Boys • Early maturation positives • Popularity, higher self-esteem • Early maturation negatives • Deviant, risk behaviors; more rigidity later • Girls • Early maturation positives • Popularity (cultural dependence) • Early maturation negatives • Lower self-esteem, eating disorders, emotions, deviant behaviors

24. Late Maturation • Boys • Late maturation positives • Higher levels of creativity, inventiveness • Late maturation negatives • Low self-esteem, low social competence • Girls • Late maturation positives • Thinner build • Late maturation negatives • Social withdrawal

25. Among the most important brain changes to take place at adolescence are those in the prefrontal cortex and limbic system.

26. The second wave…. • Longitudinal fMRI studies reveal: • Period of rapid synaptogenesis and pruning • Comparable to 1st 3 yrs of life • Growth: starts with onset of puberty • Pruning: 1% of gray matter/yr • Increased myelination (back to front) • Opportunity for massive cognitive growth and learning • Shift into Piaget’sformal operations

27. heightened arousal • Increased hormone activity • estrogen & testosterone • Sexual stimulation • Social status conflict • Increased neurotransmitter activity • Limbic system • heightened emotional sensitivity/reactivity • norepinephrine • Punishment/reward system • increased risk, stimulation-seeking behaviors • dopamine • Fluctuations in mood • Serotonin

28. (Pre) frontal lobe development • Final development of executive function • Planning/problem-solving • Impulse control • Seat of “sober 2nd thought” • Processing of emotions • Understanding/responding to emotions • Full Maturation – sometime between adolescence and early adulthood • Coincides with child-onset schizophrenia • Failure in executive functioning

29. Timing of brain maturation • Limbic system matures early in puberty • Prefrontal cortex matures several years later • Heightened need for reward/stimulation • leads to increased stimulation-seeking behaviors • Underdeveloped “sober” assessment of risks • Increased cognitive/social demands • Creates cognitive overload • Difficulty with impulse control • Time gap may explain why adolescence is a period of heightened experimentation with risky behaviors • Increased violence • kids under 18 account for 25 of violent crime in US • Drug & alcohol experimentation • Unsafe sexual activities

30. Adolescents whose prefrontal cortical development is less mature than normal are more likely to have conduct problems. Populations most at risk?

31. Social implications • What should the social attitudes be about adolescent exposure to and involvement in high-stimulation/high-risk activities? • Sexual Activity • Drugs & Alcohol • Violence

33. Teen pregnancy • 750,000 teens between 15-19 years old become pregnant every year. • 2/3rds between 18-19 years old. • African American teens have highest rate • 134/1,000 vs. 48/1,1000 Caucasian teenagers • 57% end in birth (11% of all births in US) • 14% end in miscarriage • 29% end in abortion • 82% of those pregnancies were unintended

34. risk factors • Physical • Sexual maturation • 4-5 years before psychological/emotional maturation • Becoming longer as puberty starts earlier • Brain development • Heightened activation of limbic system • Increased attraction to risky behaviors • Pre-frontal development incomplete

35. SES factors • 50% of pregnancies occur in most impoverished populations • Less opportunity for education • Less access to birth control • Reduced internal locus of control • Exposure to other risk factors • drugs, alcohol, abuse, lack of parental monitoring • Desire for family/stability

36. consequences • Should we be concerned about this? • For teenage parents • mother in particular • For baby • For families • For community • Methods of prevention?

37. Why is teenage pregnancy higher in the US?

40. Impact of substance abuse • Alcohol/drug abuse • Greater potential impairment in learning • More widespread brain damage • Repeated exposure may effect path and quality of development • Due to reduction in plasticity, this damage cannot be corrected later! • So, does this mean all experimentation with drugs/alcohol bad?

42. Should we be worried about exposure to graphic violence through media? • Why or why not?