Heritability was significantly demonstrated in SRTT (see Table 4). The genetic variation in overall LR due to genetics was 67% (p=0.025). However, there was no significant genetic variation in LR shown during the periods of early alcohol drinking, regular alcohol drinking, and heaviest alcohol drinking, although period of regular drinking did trend towards significance (h2=0.52, p=0.068). Heritability analysis of African Americans in the sample indicated that similar to the entire sample, the African Americans also have a significant SRTT score.
