Robust genetic nurture effects on education: A systematic review and meta-analysis based on 38,654 families across 8 cohorts

Abstract

Similarities between parents and offspring arise from nature and nurture. Beyond this simple dichotomy, recent genomic studies have uncovered "genetic nurture" effects, whereby parental genotypes influence offspring outcomes via environmental pathways rather than genetic transmission. Such genetic nurture effects also need to be accounted for to accurately estimate "direct" genetic effects (i.e., genetic effects on a trait originating in the offspring). Empirical studies have indicated that genetic nurture effects are particularly relevant to the intergenerational transmission of risk for child educational outcomes, which are, in turn, associated with major psychological and health milestones throughout the life course. These findings have yet to be systematically appraised across contexts. We conducted a systematic review and meta-analysis to quantify genetic nurture effects on educational outcomes. A total of 12 studies comprising 38,654 distinct parent(s)-offspring pairs or trios from 8 cohorts reported 22 estimates of genetic nurture effects. Genetic nurture effects on offspring's educational outcomes (β_{genetic nurture} = 0.08, 95% CI [0.07, 0.09]) were smaller than direct genetic effects (β_{direct genetic} = 0.17, 95% CI [0.13, 0.20]). Findings were largely consistent across studies. Genetic nurture effects originating from mothers and fathers were of similar magnitude, highlighting the need for a greater inclusion of fathers in educational research. Genetic nurture effects were largely explained by observed parental education and socioeconomic status, pointing to their role in environmental pathways shaping child educational outcomes. Findings provide consistent evidence that environmentally mediated parental genetic influences contribute to the intergenerational transmission of educational outcomes, in addition to effects due to genetic transmission.

Keywords: educational achievement; educational attainment; genetic nurture; intergenerational transmission; meta-analysis.

Figure 1

Flow chart of identification of eligible studies

Figure 2

Forest plot of multilevel random effects model for genetic nurture effects and direct genetic effects on educational outcomes Effect sizes were standardized beta coefficients, which represent how many standard deviations of change in educational outcome occur per standard deviation of change in EA PGS.