Heritability and Etiology: Heritability estimates can provide causally relevant information

Abstract

Can heritability estimates provide causal information? This paper argues for an affirmative answer: since a non-nil heritability estimate satisfies certain characteristic properties of causation (i.e., association, manipulability, and counterfactual dependence), it increases the probability that the relation between genotypic variance and phenotypic variance is (at least partly) causal. Contrary to earlier proposals in the literature, the argument does not assume the correctness of any particular conception of the nature of causation, rather focusing on properties that are characteristic of causal relationships. The argument is defended against Lewontin's (1974) locality objection and Kaplan and Turkheimer's (2021) recent critique of Genome-Wide Association Studies (GWAS).