DNA and IQ: Big deal or much ado about nothing? – A Meta-analysis

Intelligence is polygenic, highly heritable, and predicts wide-ranging life outcomes. Here, we meta-analysed the predictive validity of polygenic scores for intelligence based on the largest available genome-wide association study (or GWAS; Savage et al., 2018) for tested, phenotypic intelligence to date. Across 32 estimates from 9 independent samples, which all came from WEIRD countries and were of European ancestry (Ntotal=452,864), our meta-analytic estimate for the association between polygenic and phenotypic intelligence was ρ=.245 (p<.001, 95% CI=.184 – .307), an effect of medium size. The meta-analytic estimate varied across samples, studies, and phenotypic measures of intelligence, and even after accounting for these moderators, polygenic score predictions remained significantly heterogenous. Our findings support claims that polygenic predictions of intelligence benefit and advance research but their utility in other contexts is yet to be demonstrated.