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

Although there is substantial evidence that socioeconomic status (SES) predicts children's executive function (EF), the mechanisms underlying this association are poorly understood. This study tested the utility of two theories proposed to link SES to children's EF: 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 EF, 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 modeling, we tested simultaneous pathways from SES to EF: (a) via maternal psychological distress to harsh parenting (family stress model) and (b) 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 suggest that family functioning is an important proximal mechanism for children's EF development. This study also highlights the importance of considering SES as a multidimensional construct.