Such findings are noteworthy, not only because they highlight etiological distinctions between child and adolescent conduct problems, but also because findings of shared environmental moderation are difficult to rectify with the diathesis–stress model of G × E. How might we understand the moderation of shared environmental influences? There is another, less frequently discussed, model of G × E that predicts shared environmental moderation in particular: the ‘bioecological interaction’ (Bronfenbrenner & Ceci, 1994; Pennington et al. 2009). The logic of this model is best illustrated through Lewontin’s analogy of genetically variable seeds planted in either nutrient-rich or nutrient-deprived soil (Lewontin, 1995). Because all plants receive adequate nutrition in nutrient-rich soil, individual differences in plant height would be largely a consequence of genetic differences between plants. The environmental adversity conferred by the deprived soil, by contrast, should eventuate in a field populated largely by short plants, regardless of the plants’ genetic predispositions for height. Put differently, it may be that some adverse experiences provide such a strong ‘social push’ for a given outcome that the importance of genetic factors in these environments
