The depth of phenotypic and environmental information collected on participants makes it possible to study environmental as well as genetic influences on alcohol use outcomes. Importantly, this enables us to study the complex ways in which genetic and environmental risk are intertwined via gene–environment interaction and correlation processes. 57 , 94 , 95 It has become clear that genetic influences impact alcohol use outcomes in part by disrupting the family system. For example, genetic risk contributes to hazardous adolescent drinking by adversely impacting parent–child relationships and positive parenting practices, 96 parent–child closeness and parental monitoring, 97 and contributing to lower levels of family support, 98 as has also been found in other samples. 99 , 100 , 101 , 102
