In the present study, we systematically re-examined these three environmental factors (parental knowledge, peer deviance, and potentially stressful life events) using new methods that account for the potential correlation between twins’ level of the environment, unlike the statistical models that have historically been used to investigate GxE. In addition we assessed whether non-linear transformations of the behavioral outcome would change previously reported GxE results since some types of interactions have been shown to be scale dependent (Lynch & Walsh, 1998; Mather & Jinks, 1982).
