Developmental Psychology: Piaget, Erikson, and Kohlberg
Developmental psychology is a high-yield topic in the MCAT P/S section, tested through passage scenarios requiring stage identification and application. Piaget's cognitive development stages: Sensorimotor (birth-2 years) — object permanence develops; Preoperational (2-7 years) — symbolic thinking, egocentrism, lack of conservation; Concrete Operational (7-11 years) — conservation mastered, logical thinking with concrete objects, reversibility; Formal Operational (12+ years) — abstract reasoning, hypothetical-deductive thinking. Erikson's psychosocial stages (8 stages across the lifespan): Trust vs. Mistrust (infancy), Autonomy vs. Shame (toddler), Initiative vs. Guilt (preschool), Industry vs. Inferiority (school age), Identity vs. Role Confusion (adolescence), Intimacy vs. Isolation (young adult), Generativity vs. Stagnation (middle adult), Integrity vs. Despair (late adult). Kohlberg's moral development: Preconventional (rules followed to avoid punishment or gain reward — Stage 1 obedience, Stage 2 self-interest); Conventional (rules followed to maintain social order or gain approval — Stage 3 conformity, Stage 4 law and order); Postconventional (rules evaluated against universal ethical principles — Stage 5 social contract, Stage 6 universal principles). MCAT passages present a scenario and ask which stage best describes the behavior — know the defining characteristic of each stage, not just the name.