Development tricks that make stages stick

Secure: explores freely, upset at separation, easily comforted. Anxious: clingy, very distressed, hard to soothe. Avoidant: indifferent to caregiver, suppresses attachment needs.

Infants under ~8 months won't search for a toy hidden under a blanket — they don't understand it still exists. After object permanence develops, they'll search for it.

ZPD = what a learner can do with guidance but not yet alone. Scaffolding = teacher support that bridges this gap. Gradually remove support as competence grows.

Pre-conventional: morality based on consequences to self (punishment and reward). Conventional: morality based on social rules and laws. Post-conventional: morality based on universal ethical principles.

Germinal: fertilization through implantation (~2 weeks). Embryonic (2-8 weeks): major organs and structures form — most vulnerable to teratogens (alcohol, drugs, infections). Fetal (8 weeks to birth): growth and refinement of systems. Teratogens cause most damage during embryonic stage when organs are forming.

Thomas and Chess: Easy (40%): adaptable, positive mood, regular routines. Difficult (10%): intense reactions, slow to adapt, negative mood. Slow-to-warm-up (15%): initially withdraws, gradually adapts. Goodness of fit: match between child's temperament and parenting style predicts outcomes.

Authoritative: warm, responsive, consistent boundaries → children: confident, socially skilled, academically successful. Authoritarian: strict, low warmth, punitive → children: obedient but lower self-esteem. Permissive: warm but few rules → children: impulsive, lower achievement. Uninvolved: low warmth and low control → worst outcomes.

Physical: puberty — hormonal changes, primary and secondary sex characteristics. Cognitive: formal operational thought — abstract reasoning, hypothetical thinking. Social: Erikson's identity vs role confusion — 'Who am I?' Peer influence peaks. Risk-taking increases — prefrontal cortex not fully developed until ~25.

Fluid intelligence: raw processing speed, working memory, novel problem-solving — peaks in 20s, declines gradually. Crystallized intelligence: accumulated knowledge, vocabulary, expertise — maintained or increases into old age. Successful aging: staying physically active, mentally engaged, and socially connected.

Stranger anxiety: distress at unfamiliar people — emerges ~6-8 months when infants can distinguish familiar from unfamiliar faces. Separation anxiety: distress when attachment figure leaves — peaks ~14 months, gradually decreases. Both signal that healthy attachment has formed. Absence may indicate attachment problems.

Develops around age 4. False belief task: child understands that another person can have a false belief. Before theory of mind: children assume everyone knows what they know (egocentrism). Autism spectrum disorder often involves theory of mind deficits. Foundation of empathy and social understanding.

Stage 1 (0-1): Trust vs. Mistrust — reliable caregiving builds trust. Stage 2 (1-3): Autonomy vs. Shame — independence vs. doubt. Stage 3 (3-6): Initiative vs. Guilt — purpose vs. overrestriction. Stage 4 (6-12): Industry vs. Inferiority — competence vs. inadequacy. Stage 5 (12-18): Identity vs. Role Confusion — Erikson's signature stage. Stage 6 (young adult): Intimacy vs. Isolation. Stage 7 (middle): Generativity vs. Stagnation. Stage 8 (late): Integrity vs. Despair.

Pre-conventional (childhood): Stage 1 — obedience to avoid punishment; Stage 2 — self-interest and exchange. Conventional (adolescence/adults): Stage 3 — good interpersonal relationships; Stage 4 — law and social order. Post-conventional (few adults): Stage 5 — social contract and individual rights; Stage 6 — universal ethical principles. Gilligan's critique: Kohlberg's model is male-biased — women use an ethics of care, not just justice.

0-6 months: cooing. 6-12 months: babbling (all languages, then narrows). 12 months: first words. 18-24 months: vocabulary explosion (word spurt). 2 years: two-word utterances. 2-3 years: telegraphic speech (content words, no grammar). Chomsky's Language Acquisition Device (LAD): innate grammar mechanism — universal grammar. Behaviorist view (Skinner): imitation and reinforcement. Critical period hypothesis: language learning impaired if delayed past puberty.

Piaget's formal operations: abstract and hypothetical thinking emerges. Erikson's identity vs. role confusion: who am I? Marcia's identity statuses: diffusion, foreclosure, moratorium, achievement. Peer relationships become paramount — peer pressure and conformity peak. Adolescent egocentrism (Elkind): imaginary audience (everyone's watching me) + personal fable (I'm unique and invincible). Prefrontal cortex not fully mature until mid-20s — explains risk-taking.