School Performance and Educational Attainment as Early-Life Predictors of Age-Related Memory Decline: Protective Influences in Later-Born Cohorts.

Abstract

Evidence is accumulating that early-life characteristics and experiences contribute significantly to differences in cognitive aging. This study investigated whether school performance at age 12 predicted late-life level and rate of memory change over 15-25 years, and whether its potential protective influence on memory change was mediated by educational attainment or income. Latent growth curve models were fitted to 15-25 year longitudinal memory data from a population-based sample, stratified on age cohorts (n = 227, born 1909-1935; n = 301, born 1938-1954). A latent-level school grade variable significantly predicted both memory level and slope in later-born cohorts. Higher grades were associated with higher level and reduced decline, measured between ages 45 and 70 years, on average. In the earlier-born cohorts, grades predicted memory level, but not slope, measured between ages 66 and 81 years. Follow-up analyses indicated that the protective influence of higher school grades in later-born cohorts was partially mediated by educational attainment, but independent of income. The results suggest that higher childhood school performance is protective against age-related cognitive decline in younger or later-born cohorts, for which further education has been more accessible. Education may exert such influence through increased cognitive reserve or more well-informed health- and lifestyle decisions.