adulthood

Meaning: Adulthood is the lifespan period after adolescence, usually divided into early, middle, and late adulthood. Physical capacity generally peaks in early adulthood and declines gradually afterward. Crystallized intelligence (accumulated knowledge) tends to hold steady or rise with age, while fluid intelligence (novel problem solving, processing speed) tends to decline.

On the MCAT: Erikson places intimacy vs isolation in young adulthood, generativity vs stagnation in middle adulthood, and integrity vs despair in late adulthood. A passage describes a person, such as one mentoring younger coworkers, and asks which conflict applies. Questions may also use aging theories: disengagement theory (withdrawal from social roles is natural and expected), activity theory (staying engaged supports well-being), and continuity theory (people keep their earlier habits and preferences). Graphs may compare fluid and crystallized intelligence across age.

Common confusion: Cognitive decline is not global with age: crystallized intelligence usually holds up while fluid intelligence declines. Also, Piaget's formal operational stage begins in adolescence, so his theory has no separate adult stage, although some researchers propose postformal thinking. Identity vs role confusion belongs to adolescence, not adulthood.