Vertical pleiotropy explains the heritability of social science traits

Abstract

We contend that social science variables are the product of multiple partly heritable traits. Genetic associations with socioeconomic status (SES) may differ across populations, but this is a consequence of the intermediary traits associated with SES differences also varying. Furthermore, genetic data allow social scientists to make causal statements regarding the aetiology and consequences of SES.

Figure 1

A simplified illustration of vertical pleiotropy showing a subset of the possible intermediary phenotypes between genetic variation and phenotypic differences in social science variables. Illustrated is a schematic describing that when a GWAS is performed on, or a polygenic score is derived to predict differences in, education, genetic variation is linked to education (Panel A.). However, the means by which an association occurs is that, in part, a number of partly heritable traits are themselves associated with education as part of a phenotype pathway starting with genetic inheritance and ending with phenotypic consequences for education (Panel B.). Light blue boxes indicate sources of genetic variation where light blue arrows show the association between genetic and trait variation measured using GWAS or PGS. Dark blue shows sources of environmental variation with dark blue arrows indicating environmental associations with a trait. Pale blue indicates education as an example of a social science variable. The blue/grey boxes in panel B. show possible intermediary heritable phenotypes.