Childhood intelligence and adult health: The mediating roles of education and socioeconomic status

The longitudinal relation between childhood intelligence and various health outcomes in adulthood is now well-established. One mediational model that accounts for this relation proposes that intelligence has cumulative indirect effects on adult health via subsequent educational attainment and adult socioeconomic status (SES). The aim of the present study was to examine whether and the extent to which educational attainment and SES mediate the impact of childhood intelligence on three dimensions of adult health in Luxembourg, a country with high-quality universal public health care. We used data from 745 participants in the Luxembourgish MAGRIP study. At the age of 12, participants completed a comprehensive intelligence test. At the age of 52, they reported their educational careers, SES, and functional, subjective, and physical health status. Using structural equation modeling, we investigated the direct and indirect effects (via educational attainment and adult SES) of childhood intelligence on adult health. We found that higher childhood intelligence predicted better functional, subjective, and physical health in adulthood. These effects were entirely mediated via educational attainment and SES. The mediational processes differed depending on the health dimension under investigation: Whereas SES was crucial in mediating the effect of intelligence on functional and subjective health, educational attainment was crucial in mediating the effect on physical health. These findings held up when considering adult intelligence and were similar for women and men. Our results suggest that even excellent public health care cannot fully offset the cumulative effects of childhood intelligence on adult health. Further studies are needed to investigate the relative importance of different mediators in the intelligence–health relation while including a broader set of objective health measures.