Age differences and educational attainment across the life span on three generations of Wechsler adult scales

The pattern of cognitive ability differences across age ranges remains essentially the same regardless of educational background.

“Nonetheless, the pattern of cognitive ability differences across age ranges remained essentially the same for individuals, regardless of their educational background.”

Prior cross-sectional research shows crystallized abilities increase from adolescence through the 50s or 60s and are maintained until about age 75, then decline rapidly, while fluid abilities and processing speed peak in the 20s and decline steadily thereafter.

“In general, prior cross-sectional research shows increases in crystallized abilities from adolescence through to one’s 50s or 60s, and maintenance until about age 75, before these abilities decline rapidly into old age (Kaufman and Horn 1996); by contrast, fluid abilities and processing speed peak during one’s 20s, and then display a steady and often precipitous decline through to old age (Kaufman”

Higher educational attainment correlates with higher Full-Scale IQs.

“Higher educational attainment correlated with higher Full-Scale IQs (FSIQ).”

Prior scholars using cross-sectional methodology have long proposed maintained crystallized abilities at least through late middle age, contrasted with vulnerable working memory, processing speed, and problem solving, with decline in vulnerable abilities beginning early in one's 20s and continuing steadily through the oldest age tested.

“Prior scholars using cross-sectional methodology who examined cognitive aging have long proposed the concept of maintained crystallized abilities, at least through late middle age, contrasted with vulnerable working memory, processing speed, and problem solving (visual spatial and fluid); the sometimes dramatic decline in vulnerable abilities has shown to begin early (in one’s 20s) and continue”