The role of the ‘word gap’ for the intergenerational transmission of education: A genetically sensitive study

Children experience large differences in language learning opportunities during the early years. These differences include their mothers’ vocabulary sophistication, which may serve as a pathway for the transmission of educational attainment across generations. However, associations between vocabulary sophistication and education may be confounded by genetic factors that mothers and children share. In the E-Risk study—a longitudinal, nationally representative cohort of 1,116 British families, mothers’ naturalistic speech was recorded when their children when they were 5 years old. From the transcripts of these recordings, we derived mothers’ vocabulary sophistication. Mothers’ educational attainment at children’s age 5 years significantly predicted children’s educational attainment at age 18 years (β = .33, 95% CI [.280, .371]), and 16% of this association could be attributed to mothers’ vocabulary sophistication. Using path models with polygenic scores, we discerned genetic transmission effects (i.e., shared genetics) from environmentally mediated influences. We found that mothers’ vocabulary sophistication accounted for approximately 2% of the environmentally mediated influence on children’s educational attainment. The findings support that the ‘word gap’—differences in children’s language learning opportunities—likely plays a small causal role in the intergenerational transmission of educational attainment. Our results highlight the importance of early language environments and may inform strategies aimed at reducing the impact of family background on educational inequality.