This study tested implications of new genetic discoveries for understanding the association between parental investment and children's educational attainment. A novel design matched genetic data from 860 British mothers and their children with home-visit measures of parenting: the E-Risk Study. Three findings emerged. First, both mothers' and children's educationassociated genetics, summarized in a genome-wide polygenic score, predicted parenting --a gene-environment correlation. Second, accounting for genetic influences slightly reduced associations between parenting and children's attainment --indicating some genetic confounding. Third, mothers' genetics influenced children's attainment over and above genetic mother-to-child transmission, via cognitively-stimulating parenting --an environmentallymediated effect. Findings imply that, when interpreting parents' effects on children,