Adolescence: Cognitive, Social & Behavioral Development

G. Stanley Hall & the Invention of “Adolescence”

• 1904 – Hall publishes “Adolescence,” coining the term.
• Defines the period as “storm & stress”
  • Heightened emotions
  • Increased risk-taking
  • Hyper-sensitivity to the social world
• Early 20^{th} century context:
  • \approx 100 years ago most children left school after 6^{th}!/7^{th} grade to work.
• Great Depression (late 1920\text{s} – 1930\text{s}):
  • Jobs vanished ⇒ teens unemployed & aimless.
  • Roosevelt administration creates programs encouraging school completion.
  • By 1939, 75\% of U.S. teens attend HS ⇒ same-age cohort in a non-work setting ⇒ birth of a distinct adolescent culture.

Growth of an Adolescent Culture

• Higher HS enrollment ⇒ rising intellectual skills.
• Time allocation shift:
  • Less with parents, more with peers.
• Businesses discover teens as a lucrative market ⇒ targeted advertising ⇒ music, dress, slang diverge from mainstream.
• Instructor video clip of millennial/Gen-Z slang (TBH, Gucci, salty, shade, tea, skirt, shook, turnt, woke) illustrates a peer-generated micro-culture.

Cognitive Development During Adolescence

Piaget’s Formal Operational Stage (≈ 12^+ yrs)

• Final stage of cognitive development.
• Abilities:
  • Logical reasoning about abstract & hypothetical ideas.
  • “Scientific” problem-solving.
• Classic assessment: Pendulum Problem
  1. Variables: string length, weight mass, drop height.
  2. Formal thinker isolates one variable, controls others.
  3. Example solutions explained step-by-step in lecture.
• Outcomes:
  • Not all adolescents – nor all adults – attain stage; more common in Western cultures.

Adolescent Egocentrism (Elkind)

• Definition: Belief that one’s own thoughts/actions are the center of everyone else’s attention.
• Three manifestations:
  • Personal Fable: “My life is unique/heroic; nothing can hurt me.” ⇒ risk-taking.
  • Imaginary Audience: Constant sense of being on stage (e.g., crossing gym floor without tripping).
  • Invincibility Fable: Conviction of immunity to harm (unprotected sex, drugs, reckless driving).

Perspective-Taking Study (Blakemore et al.)

• Director vs. No-Director grid task
  • Director condition requires visual perspective taking; rule-based condition does not.
• Error rates:
  • Adults & teens equal on rule-based.
  • Teens commit significantly more errors on director task ⇒ lingering egocentrism.

Peer Relations & Popularity

Sociometric Status Categories (childhood baseline)

• Popular: many + nominations.
• Neglected: few +/- nominations.
• Average: avg +/- nominations.
• Controversial: many + & many -.
• Rejected: many - nominations (sub-types: aggressive-rejected vs. withdrawn-rejected).
• Culture matters: shy ≠ unpopular in 1990 Shanghai; trend changing by 2010\text{s}.

Shift Through Adolescence

• Elementary: popularity ≈ being well-liked.
• By 9^{th} grade: correlation between “popular” & “liked” nearly zero.
• Desired-Friendships Study (Thomas & Bowker 2013):
  • N=384, youths desired friends who were popular, liked, aggressive, not necessarily prosocial.
  • Girls with many desired friendships ↓ popularity & ↑ loneliness.

Cliques → Crowds → Couples (Dunphy trajectory)

• Early MS: Unisex cliques (≈ 6 members, family-size emotional security).
• Late MS: Multiple cliques fuse into mixed-sex crowds (e.g., jocks, brains).
• HS: Mixed-sex cliques dominate; late HS transitions to dyadic dating.

Universal Crowd Types in Affluent Cultures

1. Intellectuals / Brains / Nerds
2. Athletes / Jocks
3. Populars / Elites / Preppies
4. Deviants / Burnouts / Druggies
5. Residual / Goths / Loners

• Mean Girls cafeteria map clip used as cinematic example.
• Developmental impact:
  • Identifying as jock ⇒ ↑ risk of alcohol abuse & unprotected sex.
  • Depression trajectories: Popular & jock ↓ over time; brains ↑; deviants stable & high.

Bad Crowds & Deviancy Training

• Deviancy Training: reinforcement of antisocial talk/acts within group ⇒ entrenched delinquency.
• Hostile Attribution Bias: ambiguous acts interpreted as hostile (common in deviant teens).
• Gangs: structured delinquent crowds providing status, protection, income; escalate adolescent-limited turmoil into life-course criminality; flourish in dangerous, low-opportunity neighborhoods. Moving teens to affluent areas backfired (isolation, stigmatization).

Friendship Quality & Adult Health (Allen et al. 2015)

• Longitudinal N=171 (ages 13\to27).
• Predictors of adult health quality score:
  • High-quality early-teen friendships ⇒ better adult self-reported health.
  • Allocentrism (peer-rated) ⇒ better adult health.
• Effects remained after controlling for prior health, BMI, mood disorders, personality, SES, attractiveness.
• Interpretation: social isolation ⇒ chronic low-grade stress ⇒ impaired immunity & BP.

The Adolescent Dilemma

• Popularity path: Early pseudo-mature behaviors (alcohol, minor delinquency) ⇒ 10 yrs later ↑ substance & legal problems, ↓ social competence.
• Isolation path: Lack of peer connections ⇒ chronic stress, worse adult physical health.
• Successful navigation: Combine autonomy (resist negative peer pressure) + strong high-quality friendships.

Risk-Taking, Peers & the Brain

Risk Statistics (CDC HS Survey 2019)

• Alcohol (≥1 drink in last 30 days): 34.9\%.
• Rode w/ drinking driver (last 30 days): 21.9\%.
• Ever drank alcohol (lifetime): 66.2\% (historical sample in lecture).
• Marijuana ever-use: 40.7\%.
• Text/e-mail while driving (last 30 days): 41.4\%.

Steinberg Driving Game Experiment

• Participants N!>!100; groups 13\text{–}16, 18\text{–}22, 24^+.
• Alone: ≈ 1 crash / 15 rounds all ages.
• With peers:
  • Adolescents: \approx3 crashes.
  • Adults: no change.
• fMRI follow-up: Peer observation ↑ ventral striatum (dopamine reward) activation in teens, not adults.
• Parallel mouse study: Adolescent mice drink > alcohol when cage-mates present; adults unaffected ⇒ evolutionary conservation.

Neurobiological Model

• Puberty ⇒ limbic dopamine surge (reward accelerator).
• Prefrontal control system (brakes) lags in maturation ⇒ accelerator > brake.
• Peers magnify reward valuation ⇒ elevated sensation seeking.

Epidemiology of Morbidity & Mortality

• Physical/mental capabilities peak; yet death/disability ↑ 200\% from childhood to late adolescence due to behavioral causes (accidents, homicide, suicide, substance use).
• Arrest curve peaks 18–19 then declines.

Emotional Landscape

• Experience Sampling shows extreme mood variability: rapid swings from euphoria to despair.
• Long-term trend: Self-reported happiness declines across adolescence; girls slightly happier but similar decline slope.
• Clinical Depression: \geq2 weeks hopelessness/lethargy; rates rise in adolescence; higher in females.
• Suicide: Ideation common; completion rare (≈ 8/100,000 ages 15–19). Highest completion in mid-40\text{s}–50\text{s}.
• Non-Suicidal Self-Injury (NSSI): ≈ 33\% of HS students engage at least once; linked to impulsivity & poor emotion regulation.

At-Risk vs. Thriving Teens

Risk Factors

1. Early externalizing problems & weak emotion regulation.
2. Insecure parent attachment / poor family relations.
3. Non-nurturing environments (bullying school climate, dangerous neighborhoods).

Protective / Thriving Factors

• Superior executive functions (working memory, inhibition, cognitive flexibility).
• Presence of a mentor.
• Prosocial orientation within peer group.
• Academic success & strong schools/communities.
• Passion/talent development.
• Religious faith.
• Close family relationships.

Parent–Teen Relationship Dynamics

• Bickering: Frequent, petty arguments over daily minutiae (chores, homework) peak during puberty.
• Parents gradually grant autonomy, teens gain decision latitude ⇒ conflict declines by late adolescence.
• Negative emotions expressed at 10{:}1 ratio, yet many parents find the period rewarding.
• Myth of universally miserable parents disproved; quality time valued once power balance equalizes.

Key Take-Home Synthesis

• Adolescence emerges historically with mass schooling; characterized by unique culture, cognitive shifts, and re-wiring of social priorities.
• Cognitive gains (formal operations) coexist with egocentrism & reward-driven impulsivity ⇒ seemingly paradoxical risk behavior.
• Peer context is double-edged: essential for health & identity, yet a conduit for deviance & danger.
• Long-term outcomes hinge on balancing autonomy with connectedness, cultivating high-quality friendships, and engaging in supportive family/school environments.