This article unifies diverse theoretical and empirical approaches, providing a comprehensive review of published research on alcohol-related GxE. There are two main differences in how GxE have been investigated and conceptualized across the twin, adoption and molecular genetic literature. First, efforts to identify alcohol-related GxE have been relatively more recent for measured gene studies. Second, twin researchers utilized measures of the permissiveness or restrictiveness of socio-cultural environmental factors and described GxE as environmental moderation of genetic influences, whereas molecular genetic studies typically utilized environmental measures of adversity and framed GxE as genetic moderation of environmental influences. Though these interpretations are statistically identical, they may be indicative of the differing ways in which twin and molecular genetics researchers have ascertained their samples and conceptualized models of GxE. Compared to molecular genetic studies, twin studies are typically more epidemiologically based with larger samples and a broader range of general environments. To the degree that molecular genetics studies have used clinical populations, this may shape the use of environmental adversity versus measures of environmental constraints. Given that classical genotype studies can be used
