Socioeconomic and Genomic Roots of Verbal Ability

Abstract

Cognitive ability is one of the most potent and contentious human traits. Many issues surrounding cognitive ability especially those related to heredity is highly charged. Yet, all of the discussion on heredity has been based on non-DNA evidence. It is largely neglected that DNA and environmental data at individual level are indispensable for understanding the development of cognitive ability. In this article, we report findings from a study that uses both ability-related polygenic scores (PGSs) and a rich set of socioeconomic measures from Add Health. In an all-ethnicity sample excluding blacks, a social-science model predicts verbal ability well yielding an R2 of 17.5%. Adding two ability-related PGSs increases this R2 by 1.7%. Such models yield more accurate estimates of the effects of the PGSs and those of SES context, and provide an estimated degree to which SES context is influenced by parental genomes. Schooling and neighborhood remain important to verbal ability even after an early measure of verbal ability is adjusted in the model. Although the influence from the genome is evident, the influences of SES context are critical and cannot be dismissed.