Socioeconomic position and executive functioning from childhood to young adulthood: Evidence from Santiago, Chile.

Abstract

Optimizing cognitive development through early adulthood has implications for population health. This study aims to understand how socioeconomic position (SEP) across development relates to executive functioning. We evaluate three frameworks in life-course epidemiology - the sensitive period, accumulation, and social mobility hypotheses. Participants were young adults from Santiago, Chile who were studied from 6 months to 21 years. Family SEP was measured at ages 1y, 10y, and 16y with the modified Graffar Index. Executive functioning was assessed at ages 16y and 21y by the Trail Making Test Part B (Trails B). Analyses estimating 16y and 21y executive function involved 581 and 469 participants, respectively. Trails B scores were modeled as a function of SEP at 1y, 10y, and 16y, as the total accumulation of disadvantage, and as change in SEP between 1y and 10y and between 10y and 16y. Participants were low- to middle-income in infancy and, on average, experienced upwards mobility across childhood. Half of participants (58%) improved Trails B scores from 16y and 21y. Most (68%) experienced upward social mobility between infancy and 16y. When examined independently, worse SEP measured at 10y and 16y related to worse (longer time to complete) Trails B scores at Age 21 but did not relate to the other outcomes. After mutual adjustment as a test of the sensitivity hypothesis, no SEP measure was independently related to any outcome. Testing the accumulation hypothesis, cumulative low SEP was associated with worse cognitive performance at 21y (β=3.6, p=0.04). Results for the social mobility hypothesis showed no relation to cognitive scores or to change in cognitive scores. Comparing all hypotheses, SEP at 16y explained the most variability in executive functioning at 21y, providing support for the sensitive period hypothesis. Results indicate that experiencing cumulatively low socioeconomic position from infancy to adolescence can have a negative impact on cognitive functioning in young adulthood. Findings also provide evidence in support of adolescence as a key developmental period during which SEP can most strongly impact cognitive functioning.