Aging, cohorts, and verbal ability

Objectives. Age-related differences in cognitive abilities observed in cros s-sectional samples of individuals varying in age may in part be spurious d ue to the effects of cohort differences in schooling and related factors. T his study examined the effects of aging on cognitive Function controlling F or any and all differences in cohort-based social experiences of different age groups. Methods. We examined age-related patterns in a measure of verbal ability us ing 14 repeated cross-sectional surveys from the General Social Survey (GSS ) over a 24-year period. Results. The raw GSS data show the expected age-related growth and decline in vocabulary knowledge, but these age differences are reduced when adjuste d thr cohort differences. There is evidence of small age-related patterns i n vocabulary knowledge within cohorts, but the curvilinear contributions of aging to variation in verbal scores account for less than one-third of 1% of the variance in vocabulary knowledge, once cohort is controlled. Cohort differences in schooling contribute substantially to this effect. Discussion. Within-age-group variation in vocabulary knowledge is vastly mo re important than age differences per se, and the complexities of the relat ionship of verbal skills to historical differences in the experience of sch ooling present an interesting avenue for future research.