No major differences were observed in the distribution of phenotypes in the three most represented ethnic populations, Caucasians, African Americans, and Hispanics, shown in Table 3a. Most subjects reported drinking about two drinks on days that they drank, and endorsed fewer than two abuse or dependence symptoms total. The distribution of lifetime number of blackouts was greatly skewed, which inflated the mean, but otherwise seemed in agreement with other samples (Nelson et al., 2004). The averages for each of the phenotypes were higher in the population of smokers than in individuals who had never smoked, as seen in Table 3b. This increase was significant for both the number of alcohol abuse and dependence symptoms as well as the number of blackouts, but not for average number of drinks nor number of quit attempts. The four phenotypes are somewhat correlated with the exception of average number of drinks with number of blackouts, which is uncorrelated, Table 3c.
