a phenotype, i.e., the total contribution of all genes influencing the phenotype. Gene-environment interaction in this context means that the overall importance of genetic variance differs across environments. In contrast, most GxE research in fields outside behavior genetics has studied measured candidate genes. These studies test whether the association of a specific genetic variant with a given outcome varies across different environments. We refer to these studies as cGxE (where cG refers to candidate gene), and they are the focus of this review.
