Clinical and basic research indicate that 1) lower sensitivity to ethanol’s effects is positively associated with high ethanol consumption (e.g., Draski and Deitrich, 1996; Schuckit and Gold, 1988); 2) the ability to display greater levels and quicker development of tolerance (a reduction in ethanol’s effects after prior treatment with ethanol) to ethanol’s effects is associated with excessive ethanol consumption and the development of alcoholism (Lê and Mayer, 1996); 3) the expression of anxiety-like behavior under basal and/or withdrawal conditions has also been associated with excessive ethanol consumption (Heilig et al., 2010a, 2010b; Kirby et al., 2011; Pautassi et al., 2010; Thorsell, 2010); and 4) the expression of low- to moderate-dose ethanol-induced stimulation [which is modeled in rodents by increased motor activity/approach behavior (Chappell and Weiner, 2008; Faria et al., 2008; Wise and Bozarth, 1987), aggression (Chiavegatto et al., 2010), and social facilitation (Varlinskaya and Spear, 2009, 2010)] is associated with an individual’s propensity to abuse alcohol. Interestingly, there may be pharmacological validity for this behavioral phenotype, such that the histaminergic (c.f., Panula and Nuutinen, 2011 and references therein) and ghrelin
