to the behavioral under-control-disinhibition theory of alcohol dependence, in which individuals are genetically predisposed to impulsivity and externalizing behavior through neurological pathways (Dick et al. 2010; Villafuerte et al. 2012). These heritable traits may manifest as conduct disorder or other externalizing problems in childhood, and as alcohol or drug dependence in adulthood when these substances are more accessible (Dick et al. 2006a). In addition, conditions such as marriage and employment can serve as external social control functions in adulthood, particularly when they are rewarding, reducing the effects of behavioral undercontrol-disinhibition and related genotypes on alcohol use (Eitle et al. 2010; Heath and Nelson 2002; Umberson et al. 2010). Consequently, in combination with ineffective social control, permissive social norms, and exposure to problem drinking through deviant peers, genetic risk for behavioral disinhibition may lead to alcohol misuse and dependence (Dick et al. 2009; Zucker et al. 2011); conversely, when opportunity to drink is constrained and/or social norms are strongly present, genetic risk for disinhibition may find more limited expression.
