Two forms of gene-environment interplay are particularly relevant to prevention science and to the three naturalistic experimental designs described in this manuscript: gene × environment interaction (GxE) and gene-environment correlation (rGE). In one form of GxE, psychopathology may result from an inherited liability to disorder (diathesis) that is manifested under particular (stress-inducing) environmental conditions. This form of GxE is consistent with diathesis-stress models of development. The literature has many examples of diathesis-stress forms of GxE from parent-offspring adoption studies (e.g., Cadoret et al., 1995) and twin studies (e.g., Kendler et al., 1995). For example, an adoption study showed that infants whose birth mother showed elevated levels of antisocial behavior were more sensitive to the stress of living with a depressed mother (Leve et al., 2010). A second form of GxE, differential susceptibility (or biological sensitivity to context), has been proposed more recently (Belsky & Pluess, 2009; Ellis et al., 2011). Differential susceptibility theory postulates that heritable factors increase sensitivity to the environment, resulting in more benefit from favorable environments and more detriment from adverse environments. Empirical tests of differential susceptibility
