The role of parental genotype in predicting offspring years of education: evidence for genetic nurture

Similarities between parent and offspring are widespread in psychology; however, shared genetic variants often confound causal inference for offspring outcomes. A polygenic score (PGS) derived from genome-wide association studies (GWAS) can be used to test for the presence of parental influence that controls for genetic variants shared across generations. We use a PGS for educational attainment (EA3; N approximate to 750 thousand) to predict offspring years of education in a sample of 2517 twins and both parents. We find that within families, the dizygotic twin with the higher PGS is more likely to attain higher education (unstandardized beta = 0.32; p < 0.001). Additionally, however, we find an effect of parental genotype on offspring outcome that is independent of the offspring's own genotype; this raises the variance explained in offspring years of education from 9.3 to 11.1% ( increment R-2 = 0.018, p < 0.001). Controlling for parental IQ or socioeconomic status substantially attenuated or eliminated this effect of parental genotype. These findings suggest a role of environmental factors affected by heritable characteristics of the parents in fostering offspring years of education.

Automated summary

The study found that dizygotic twins with higher polygenic scores for educational attainment are more likely to achieve higher education within families. Additionally, parental genotype also influences offspring outcomes independently of the offspring's own genotype, contributing to variance in offspring years of education. Control for parental IQ or socioeconomic status can mitigate or eliminate the effect of parental genotype on offspring education.