did not gain widespread recognition outside the field of twin research. It was not until the influential Science publication by Caspi and colleagues (Caspi et al., 2003) attributing part of the genetic sensitivity to the depressogenic effects of stressful life events to variations in a specific DNA sequence (a polymorphism in the serotonin-transporter-linked polymorphic region [5-HTTLPR]) that gene-environment interaction research became a widely-recognized area of study outside the field of behavior genetics. However, an important distinction arose between the GxE work conducted in the field of behavior genetics, and the widespread adoption of GxE by other fields, particularly the social sciences. Historically, the research conducted by behavior geneticists focused on “latent” genetic influences. This means that the importance of genetic factors is estimated statistically by phenotypic similarity across individuals with different degrees of genetic and environmental sharing, using methodologies such as family, twin, and adoption studies (Bergeman & Plomin, 1989). This method estimates the overall importance of genetic effects on 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
