Learning to give: Both genetic and shared environmental influences are reflected in the association between educational attainment and prosocial behaviour

Prosocial behaviours are more commonly found among the higher educated. We examined to what extent genetic effects on prosocial behaviour captured by polygenic scores for educational attainment and cognitive performance can be detected. We apply a combination of an extended family approach using sibling fixed effects with polygenic scores to participants and their siblings in the Wisconsin Longitudinal Study. These models better capture shared environmental influences on prosocial behaviour. We find that those with a higher genetic propensity to spend more years in education were more likely to have engaged in forms of formal prosocial behaviours, that is, blood donation, charitable giving and volunteer work. We found no clear association between the polygenic score for educational attainment and informal helping. The polygenic score for educational attainment explained ∼2% of the variance in formal prosocial behaviour. The association was substantially reduced when the highest level of education respondents attained was taken into account. Shared environmental influences among siblings did not affect the association of cognitive performance with formal prosocial behaviour. Shared environmental influences were responsible for about one-quarter of the association between educational attainment and formal prosocial behaviour. While the polygenic score for educational attainment could explain as little as ∼2% of the variance in formal prosocial behaviour, including it in the model helps us to better understand the pathways of inter-generational transmission and direction of causality in the association between educational attainment and prosocial behaviour.