Development Through the Lifespan - Adolescence

Conceptions of Adolescence

• Tribal and village societies: Brief adolescence.
• Industrialized nations: Extended adolescence.
  • Early adolescence (ages 11-14): Rapid pubertal change.
  • Middle adolescence (ages 14-16): Puberty nearly complete.
  • Late adolescence (ages 16-18): Full adult appearance; anticipation of adult roles.

Hormonal Changes

• Tremendous gains in body size are driven by growth hormone and thyroxine.
• Sexual maturation involves different hormones for girls and boys.
  • Girls: estrogen and adrenal androgens.
  • Boys: androgens, especially testosterone.
  • Both sexes: Estrogens combined with androgens stimulate gains in bone density.

Sex Differences in Adolescent Body Growth

• Boys:
  • Growth spurt starts around age 12.5.
  • Shoulders broaden, longer legs.
  • Gain more muscle, greater aerobic efficiency.
• Girls:
  • Growth spurt starts around age 10.
  • Hips broaden.
  • Add more fat.

Motor Development and Physical Activity

• Girls' gross motor performance slows, leveling off by age 14.
• Boys show a dramatic spurt in strength, speed, and endurance throughout teenage years.
• Regular sports and exercise improve:
  • Motor performance.
  • Cognitive and social development.
  • Physical and mental health.
• There is a decline in free-time physical activity from ages 9 to 17 among U.S. boys and girls.

Sexual Maturation

• Primary sexual characteristics:
  • Maturation of reproductive organs.
  • Girls: menarche (average age 12.5).
  • Boys: spermarche (average age 13.5).
• Secondary sexual characteristics:
  • Other visible changes signaling sexual maturity.
  • Girls: breasts.
  • Boys: facial hair, voice change.
  • Both: underarm and pubic hair.

Individual Differences in Timing of Puberty

• Factors influencing pubertal timing:
  • Heredity.
  • Nutrition, exercise, body fat.
  • SES (Socioeconomic Status).
  • Ethnicity.
  • Developing versus industrialized countries.
  • Early family experiences.
  • Secular trends.

Adolescent Brain Development

• Expansion of synaptic connections supports gains in executive function, reasoning, problem-solving, and decision-making.
• Cognitive-control network still developing: inhibition, planning, and delay of gratification are not fully mature.
• Changes in emotional/social network outpace development of cognitive-control network, leading to self-regulation difficulties.
• Adequate sleep is essential for emotion regulation and academic achievement.

Reactions to Pubertal Changes

• Reactions depend on prior knowledge, family support, and cultural attitudes.
• Mixed feelings in response to menarche and spermarche: boys get less social support, turn to reading material or websites.
• Generational improvements: parents are more open about puberty; youths are better informed.
• Some cultures celebrate with an initiation ceremony, marking puberty as a significant milestone.

Adolescent Moodiness

• Linked to more negative life events; also, more emotionally reactive to them.
• Moods of younger adolescents are less stable:
  • Highs in peer settings and leisure activities.
  • Lows in adult-structured settings.
  • Influenced by weekend expectations.

Parent-Child Relationships

• Rise in conflict:
  • Has adaptive value: psychological distancing.
  • Different views of adolescent readiness for responsibility.
• Most conflict is:
  • Mild, subsides over time.
  • Balanced by affection and support.
• Positive problem-solving reduces conflict.

Consequences of Pubertal Timing

• Girls:
  • Early-maturing: unpopular, withdrawn, low in confidence, less positive body image, more deviant behavior, at risk for lasting difficulties.
• Boys:
  • Early-maturing: popular, athletic stars, leaders, more positive body image, viewed as well-adjusted but report psychological stress and depressed mood, more deviant behavior.
  • Late-maturing: popular, sociable, school leaders, positive body image, transient emotional difficulties.

Factors Influencing Pubertal Timing Effects

• Cultural ideals of physical attractiveness.
• Fitting in with peers' physical maturity.
• Body image strongly predicts youths' self-esteem.
• Contexts that increase the risk of deviant peer associations and behaviors:
  • Economically disadvantaged neighborhoods.
  • Harsh, inconsistent parenting.

Nutrition in Adolescence

• Nutritional requirements increase.
• Poor diets are common:
  • Skipping breakfast.
  • Eating at fast-food restaurants.
  • Iron, vitamin-mineral deficiencies.
• Family meals are associated with a healthier diet.

Eating Disorders

• Risk factors for girls:
  • Reach puberty early.
  • Grow up in homes with a focus on weight and thinness.
  • Body dissatisfaction and severe dieting are strong predictors.
• Three most serious eating disorders:
  • Anorexia nervosa.
  • Bulimia nervosa.
  • Binge-eating disorder.

Adolescent Sexuality

• Hormonal changes lead to increased sex drive.
• North American attitudes are relatively restrictive, with contradictory messages from media, culture, and family.
• Influences of sexualized media exposure:
  • More exposure predicts increased sexual activity.
  • Internet pornography can increase adjustment problems.
• Attitudes of U.S. adolescents and adults toward nonmarital sex have become more accepting.
• A substantial percentage of U.S. teenagers are sexually active.

Characteristics of Adolescents Who Engage in Early Sexual Activity

• Personal: early pubertal timing, childhood impulsivity, weak sense of control over life events.
• Family: economically disadvantaged home/neighborhood, divorce, stepfamily or single parent, large family, weak parental monitoring, disrupted parent-child communication.
• Peer: sexually active friends and older siblings, alcohol and drug use, delinquency.
• Educational: poor school performance, lower educational aspirations.

Contraceptive Use

• 14% of U.S. sexually active teenagers do not use contraception consistently.
• Reasons: peer pressure and heightened emotions, unrealistic about consequences, not knowing where to get it or how to discuss it with a partner.
• Challenges: believe parents are not supportive, school sex education offers incomplete information, concerned about health practitioner confidentiality.

Sexual Orientation

• 5% identify as lesbian, gay, bisexual; 2–3% are unsure.
• Impact of heredity:
  • Male homosexuality may be X-linked.
  • Prenatal sex hormones may modify brain structures.
  • Gay men: later in birth order and have a greater number of brothers.

Lesbian, Gay, and Bisexual Youths: Coming Out to Oneself and Others

• Feeling different (ages 6-12); different activity choices.
• Confusion (early adolescence); realize same-sex attraction:
  • Inner struggle, isolation, risky behavior.
  • May choose heterosexual dating.
• Self-acceptance (end of adolescence), but tell others?
  • Tell trusted friends first.
  • Having a same-sex relationship often leads to telling parents.
  • Parental understanding is a key predictor of adjustment.
  • A supportive community is easier to find in large cities.

Sexually Transmitted Infections (STIs)

• On average, 1 out of 5 sexually active teens has an STI.
  • Females are more easily infected through heterosexual transmission.
  • Oral sex is an underestimated mode of transmission.
• At greatest risk: low-SES teenagers who feel hopelessness.
• Can lead to sterility and life-threatening complications.
• Teenagers are often poorly informed about STIs and how to protect themselves.

Adolescent Pregnancy and Parenthood

• About 625,000 U.S. teenage pregnancies in the most recently reported year; 11,000 younger than age 15.
• 1 in 4 ends in abortion.
• 89% of adolescent births are to unmarried mothers.

Factors Associated with Adolescent Parenthood

• Low parental warmth, neglect, abuse.
• Repeated parental divorce.
• Poor school achievement.
• Alcohol or drug use.
• Aggressive and antisocial behavior.
• Neighborhoods with deviant peers.
• Low SES.

Risks for Teenage Mothers and Babies

• Low educational and occupational attainment.
• More time as a single parent; absent father.
• Multiple teenage pregnancies.
• Financial difficulties.
• Pregnancy and birth complications.
• Weak parenting skills, often harsh and abusive.

Teenage Pregnancy Prevention

• More effective sex education.
• Skills for handling sexual situations.
• Information on and access to contraceptives.
• Building academic and social competence.
• Expanding educational, vocational, and employment opportunities.

Interventions for Adolescent Parents

• Health care.
• Encouragement to stay in school.
• Job and life-management training.
• Parenting instruction.
• Adult mentors, social support.
• Affordable childcare.
• Father support.

Adolescent Substance Use and Abuse

• Severe concerns:
  • One-time heavy use impairs judgment; risks injury and death.
  • Addictive nature of substances can lead to abuse.
• By the end of high school:
  • 6% regularly smoke.
  • 17% report recent heavy drinking.
  • 21% have used cannabis.

Substance Use vs. Abuse

• Occasional experimenters: psychologically healthy, sociable, curious.
• Abusers:
  • Impulsivity, hostility in early childhood.
  • Drug-taking starts earlier.
  • Low SES.
  • Family mental health problems, substance abuse.
  • Child abuse.
  • Poor school performance.
  • Weak cognitive control and elevated sensation seeking.

Substance Use Prevention and Treatment

• Good school and community programs:
  • Promote effective parenting.
  • Teach skills to resist peer pressure.
  • Reduce social acceptability of drugs.
• Teaching effective strategies for coping with stress.
• Academic and vocational training.
• Gradual improvements to boost self-efficacy.
• Family and individual therapy to treat drug abuse.

Piaget's Formal Operational Stage

• Hypothetico-deductive reasoning:
  • Problem-solving based on a hypothesis, deducing logical, testable inferences.
  • Begins with possibility and proceeds to reality.
• Propositional thought:
  • Evaluating the logic of verbal propositions without referring to real-world circumstances.

Follow-Up Research on Formal Operational Thought

• School-age children show glimmerings of formal operational thought:
  • In simplified situations; with props in make-believe play.
• Adolescents are considerably more competent:
  • Reason about more variables simultaneously.
  • Grasp logical necessity.
• Formal operations may not be universal:
  • Training and context contribute.
  • Schooling is powerfully influential.

Information-Processing Gains

• Working memory.
• Inhibition.
• Attention.
• Planning.
• Strategies.
• Knowledge.
• Metacognition: awareness of thought.
• Cognitive self-regulation.

Scientific Reasoning

• Ability to distinguish theory from evidence and use logical rules to examine their relationship:
  • Improves steadily from childhood into adolescence.
  • Development continues into adulthood.
• Contributing factors:
  • Working memory capacity.
  • Exposure to complex problems.
  • Metacognitive understanding.

Consequences of Adolescent Cognitive Changes

• Self-consciousness and self-focusing:
  • Imaginary audience.
  • Personal fable.
• Idealism and criticism.
• Decision-making:
  • Seeks immediate rewards; increased risk-taking.
  • Often does not evaluate options; falls back on well-learned judgments.

Sex Differences in Mental Abilities

• Verbal - girls tend to do better:
  • Earlier development of the left hemisphere.
  • More verbal stimulation.
  • Language arts considered "feminine."
  • Boys are poorer in writing.
• Math - boys tend to do better on tests of complex reasoning:
  • Advantaged in numerical memory, spatial reasoning.
  • Math considered "masculine"; parental bias.
  • Boys also tend to acquire more specialized computer knowledge.

Sex Differences in Spatial Abilities

• Gender gap favoring males:
  • Mental rotation tasks (large).
  • Spatial perception tasks (considerable).
  • Spatial visualization tasks (weak or nonexistent).
• Male spatial advantage is present throughout life.
• Contributing factors:
  • Heredity, but the path of influence is unclear.
  • Experience: manipulative tasks, action video games.
  • Adult encouragement.
• Early intensive training can override sex differences.

School Transitions in Adolescence

• Grades decline with each transition:
  • Higher academic standards.
  • Less supportive teaching-learning environment.
  • For ethnic minorities, fewer same-ethnicity peers.
• Decline in liking for school, academic motivation, and self-esteem.
• Additional strains (e.g., poverty, family disruption) increase the risk of self-esteem and academic difficulties.

Helping Adolescents Adjust to School Transitions

• Parent involvement, monitoring.
• Close friendships.
• Fewer transitions, K-8 schools.
• Smaller units within schools.
• Same-ethnicity peers.
• Homeroom teacher relationships.
• Classes with familiar peers or a constant group of new peers.

Supporting Academic Achievement

• Child-rearing practices: authoritative parenting, joint decision-making, parent involvement in education.
• Peer influences: valuing high achievement.
• School characteristics: warm, personal teaching, learning activities that promote high-level thinking, opportunities to break out of low academic tracks.
• Employment schedule: limited hours of part-time employment, high-quality vocational education.

Factors Related to Dropping Out

• Low grades, low academic self-esteem.
• Lower attendance, pay less attention.
• No extracurricular involvement.
• Parents: uninvolved, limited education.
• Grade retention.
• Large, impersonal schools.
• Frequent peer victimization.
• General education, vocational tracks.

Dropout Prevention Strategies

• Intensive remedial instruction.
• Personalized counseling.
• High-quality vocational education.
• Addressing personal factors related to dropout: parent involvement, flexible work-study arrangements.
• Extracurricular participation.