Presence of alcoholism in the family covaries with behavioral and neuroimaging measures of binge drinking (Ehlers et al., 2007; Kokavec & Crowe, 1999). Alcohol expectancies have been shown to be a genetically influenced characteristic having a heritability between 0.4 and 0.6 (Heath et al., 1999; Schuckit et al., 2001), with greater alcohol consumption in high-risk than in low-risk control families (Newlin & Thomson, 1990). After the consumption of the lower or higher ethanol dose (approximately three or five drinks, respectively), men with high risk for alcoholism reported significantly less intense feelings of intoxication compared with low-risk men (Ehlers & Schuckit, 1988; O'Malley & Maisto, 1988; Schuckit, 1980, 1984, 1988). As outlined above, individuals who are homozygous for the ALDH2 gene are less likely to binge drink (Luczak, Wall, Shea, Byun, & Carr, 2001), which needs to be considered in such studies.
