internalizing behavior, externalizing behavior, social competence, and school performance (G×E interaction) during early childhood, amplifying child outcomes over time. The third aim is to identify the mechanisms of G×E interaction. We focus on dyadic interactions between the adoptive parent and adopted child to examine how, when, and why G×E interactions occur. G×E interactions are hypothesized to be explained by their effects on the reciprocal, genetically influenced processes between parent and child. Specifically, child evocative G×E interactions would be indicated when heritable characteristics of the child evoke more adverse or more favorable parental response in some family environments but not in others, and child sensitivity G×E interactions would be indicated when heritable characteristics make the child more sensitive to differences between favorable and adverse family environments. An illustration of the first three study aims and the EGDS conceptual model is provided in Leve et al. (2007). The fourth aim was implemented during the second phase of funding and includes an examination of early responding systems that are susceptible to both genetic and environmental influences and are thought to serve as precursors to the primary outcomes of interest. In this aim, executive function (a precursor to externalizing problems), early literacy skills (a
