Although males generally exhibit higher levels of AD, the difference in both mean and variance of maximum drinks between the sexes and the presence of only five affected women in the sample led us to consider only males in the primary analyses. Of the 127 women queried, 41% reported never having consumed a single drink, contributing to a variance in maximum drinks among females of 32.4, compared to 122.8 among males. Distribution of maximum drinks by sex can be seen in Supplemental Figure 1. The magnitude of the sex-based differences in AD, maximum drinks, and lifetime abstention rates – despite high levels of alcohol consumption by some male family members – suggests that cultural factors may differentially influence drinking behavior by sex. The similarity in flushing rate (36.9% among males and 37.3% among females), a phenotype mediated entirely by biological factors, supports an environmental (i.e. cultural) explanation for the substantially lower rate and magnitude of drinking by women. Additionally, the heritability of maximum drinks and AD in males are 0.49 and 0.46, respectively, but non-significant in females, further reinforcing that,
