Verbal Working Memory Predicts Twice the Growth Rate in Math Skills for Children from Low- Income Homes Relative to Their Higher-Income Peers.

Working memory (WM) and socioeconomic status (SES) associations with math achievement are well established, but little work has considered whether WM contributions are the same across SES strata. Here, we focus on the extent to which verbal WM predicts math differently for children in low vs. higher SES homes in the US to disentangle how these relations might play out across development in differently resourced contexts, as well as the magnitude of these relationships across SES. Using data from a nationally representative sample of 13,527 children, we estimated a parallel process model to analyze the relation among the starting points and growth of verbal WM and math skills through elementary school. A multi-group model was used to compare the relative strength of associations between verbal WM and growth in math skills between low-income and not-low-income students. Results indicated that students with higher initial verbal WM levels developed math skills faster than those with lower verbal WM levels, especially in low-income households where verbal WM's effect size was nearly double relative to estimates for children in higher-income homes. Findings highlight the importance of providing families with the necessary resources to help children thrive in adverse contexts.