Habituation of heavy drinking and associated alcohol-related expectancies resulting from the uncontrolled context in which adolescent drinking usually occurs — a context that is arguably more conducive to excessive drinking than contexts in which adults and more extensive social controls are present — cannot be either confirmed or ruled out as a causal mechanism because of the lack of data in the NESARC on patterns and contexts of drinking during adolescence. At the same time, the argument that both early initiation of drinking and risk for AUD might be manifestations of a more general deviance syndrome (Jessor and Jessor, 1977; Newcomb and McGee, 1991) or of pre-existing impairment of executive skills regulating decision making (Goudriaan et al., 2007; Johnson et al., 2008) was countered by the strong associations between the two in the low-risk sample, which excluded individuals with other indicators of deviance and/or poor ECF. Nevertheless, before we can reject a mediating role of selectivity it will be critical to determine whether the rare low-risk sample members who initiated drinking before age 18 were characterized by AUD risk factors
