Socioeconomic status and executive function in early childhood: Exploring proximal mechanisms

Although there is substantial evidence that socioeconomic status (SES) predicts children’sexecutive function, the mechanisms underlying this association are poorly understood. This study tested the utility of two theories proposed to link SES to children’s executive function: the family stress model and the family investment model. Data came from the Midwestern Infant Development Study (N = 151). To measure SES, parental education and income were assessed during pregnancy, and income was also assessed when children were 6 and 36 months old.Children’s executive function, operationalized as working memory/inhibitory control (WMIC)and self-control, was assessed at 36 months of age, along with potential mediators including maternal psychological distress, harsh parenting, and cognitive stimulation. Using structural equation modelling, we tested simultaneous pathways from SES to executive function: 1) viamaternal psychological distress to harsh parenting (family stress model), and 2) via cognitive stimulation (family investment model). Of the SES measures, lower education predicted poorer WMIC directly and indirectly via greater maternal psychological distress. Lower education also predicted poorer self-control via greater maternal psychological distress; this effect was partially suppressed by an indirect path from lower education to better self-control via greater psychological distress and increased harsh parenting. Cognitive stimulation did not act as a mediator. Income was not directly or indirectly associated with EF. These findings provide partial support for the family stress model and are contrary to the predictions of the family investment model, suggesting that SES’ impact on family functioning is particularly important for the development of children’s executive function.