PHYSICAL DEVELOPMENT DURING ADOLESCENCE PSY 226: Child and Adolescent Development

Learning Objectives (1) Differentiate between adolescence and puberty (2) Describe biological and environmental factors involved the pubertal process (3) Explain how the timing of puberty relates to developmental outcomes for females and males

Adolescence Age Periods Early: – Tweens 9-12 – not children, not teens

Adolescence Age Periods Middle: 14-16

Adolescence Age Periods Late: 16-19

Adolescence Age Periods Emerging adulthood: Early 20’s – Financially independent? – Separated from parents?

Adolescence – Two Views “Storm and Stress” (G. Stanley Hall) – Troubled and troubling – Adolescence is social construction “Resources to be Nurtured” (R. Lerner) – Not problems to be fixed! – Positive youth development

Puberty Reaching sexual maturity and the ability to reproduce – Girls: Onset of menarche 11-14, avg years – Boys: First ejaculation 13-14, followed by nocturnal emissions (“wet dreams”)

Puberty is a Process Hypothalamus Pituitary Gland Hormones * Growth * Gonads (sex organs) -Androgen -Estrogen

Where’s the Environment? Can you think of environmental factors that might affect the timing or process of puberty?

Environmental Influences Nutrition Body Fat – Obesity (expedite) Fat cells secrete the protein leptin that signals estrogen – Athletics (delay) – Eating Disorders (delay) Endocrine-Disruptive-Chemicals – Cause over- or under-production of sex hormones – Found in many everyday products– including metal food cans, plastic bottles, detergents, flame retardants, food additives, toys, cosmetics, and pesticides. Source: Susan Euling et al. (2008) Pediatrics

The Transition to Adolescence: Pubertal Timing and Development Chronosystem Questions: Do you think the timing of puberty matters? If so, how? What outcomes might it effect? Are the effects the same for boys and girls?

Puberty in Context “So, in other words, the meaning of the timing of the pubertal process is shaped by the social contexts in which it occurs.” -Joseph L. Mahoney, Nov. 18, 2015

What Effects the Meaning? (1) Gender (2) Cumulative Stress Model – the combination of puberty, school change, peer group changes, academic changes, family conflict, family changes – High emotional toll – Pressure to date and have sexual relations – Teasing and sexual harassment from peers

What Effects the Meaning? (3) Body Satisfaction – White youth have lowest body satisfaction – Focus on thinness runs counter to hips, thighs, waist, and weight increases Linked to depression and eating disorders Anorexia/bulimia often first seen in adolescence 20% of teens with anorexia will starve to death

Early Pubertal Development for Girls: The Deviancy Process 1.Viewed by others as more mature 2.Enter into relationships with older peers 3.Exposed to “Advanced” social norms * Beliefs, attitudes, and behaviors 4. Enter the typical process of norm-breaking earlier Hypothesis: If early maturing girls seek out peers consistent with their biological age, rather than their chronological age, then they may be accelerated in adolescent social behaviors including deviance.

Pubertal Timing and Antisocial Behavior Early PubertyAnti-social Behavior Early Puberty Perception of Maturity Older Peers Advanced Social Norms Anti-social Behavior

Categories of Maturation EARLY – before age 11 Not Early – Ages – Ages – After age 13 Sources: Graber, 2013; Magnusson (1988); Stattin, Kerr, & Skoog (2011)

Pubertal Timing and Relationships with Older Peers at age 14.5 Sources: Graber, 2013 Magnusson (1988); Stattin, Kerr, & Skoog (2011)

Pubertal Timing and Romantic Involvement at age 14.5 Sources: Graber, 2013 Magnusson (1988); Stattin, Kerr, & Skoog (2011)

Pubertal Timing and Sexual Intercourse at age 14.5 (percent) Sources: Graber, 2013 Magnusson (1988); Stattin, Kerr, & Skoog (2011)

Percent Drunk in the Last Year Chronological Age % Sources: Graber, 2013 Magnusson (1988); Stattin, Kerr, & Skoog (2011)

Norm-Breaking (age 14.5) ignoring parents, stay out late, cheat, play truant, smoke hashish, get drunk, loiter, steal Pubertal Timing Sources: Graber, 2013 Magnusson (1988); Stattin, Kerr, & Skoog (2011)

Expected Sanctions from Friends for Violating Norms Pubertal Timing Sources: Graber, 2013 Magnusson (1988); Stattin, Kerr, & Skoog (2011)

Number of Children at Age 25 Pubertal Timing Sources: Graber, 2013 Magnusson (1988); Stattin, Kerr, & Skoog (2011)

Teen Parents (> age 20) U.S. has the highest rate of teen pregnancy in the industrialized world – k teen pregnancies each year 50% child is raised by single teen mom – 45% aborted/miscarriage (no live birth) – 5% adopted

Consequences of Early Childbearing Teen moms are less ready to parent – See their kids as especially difficult to raise – Spend less time interacting with them – Kids are more apt to develop academic and conduct problems, engage in early sexual activity Dire Consequences for Teen Moms – Often limits education and career options – School dropout, especially if teen mom twice

Percent Attended College at Age 25 Pubertal Timing Sources: Graber, 2013 Magnusson (1988); Stattin, Kerr, & Skoog (2011)

Pubertal Timing and Antisocial Behavior Early Puberty Perception of Maturity Older Peers Advanced Social Norms Anti-social Behavior

Early Puberty Perception of Maturity Older Peers Advanced Social Norms The Whole Process Depends on Exposure to a Mixed-Gender School Context Presence of a Non-Related Adult Male at Home (boyfriend, step father) Family Stress Male Anti-social Behavior Sources: Graber, 2013 Magnusson (1988); Stattin, Kerr, & Skoog (2011)

Early Puberty and Boys’ Development Several modest benefits for early maturation, but less pronounced in recent studies – Popularity with peers – Physical competence (athletics) – Positive feelings about the physical changes Some risks too – Higher truancy, minor delinquency, substance use – Not linked to clinical levels of disorder Late maturing boys – Linked to depression and externalizing problems, but not consistently (J. Graber, 2013)

Learning Objectives (1) Differentiate between adolescence and puberty (2) Describe biological and environmental factors involved the pubertal process (3) Explain how the timing of puberty relates to developmental outcomes for females and males

Student Presentation Health and Sleep (p. 477) School start times and the sleep-wake cycle of adolescents