Consistent with our hypothesis, higher alc-PRS was associated with greater alcohol use among EAs. Social support from friends (but not family) was associated with lower levels of alcohol use among EAs in the whole sample. In addition, we found evidence of an interaction effect between alc-PRS and perceived social support from friends in relation to alcohol use, such that high levels of friend support attenuated/buffered the association between alc-PRS and alcohol use. Our finding is consistent with prior research conducted in EAs indicating a buffering effect of social support on measured genetic risk (Reinelt et al., 2015; Su et al., 2019). Previous studies using twin-designs have also demonstrated interaction effects between genetic factors and social support; however, some studies found that genetic influences were stronger when social support was higher (Jarnecke & South, 2014). Barr et al. (2017) found that genetic influences on alcohol use were stronger when social support was higher for women, and the opposite was found for men. Differences in G×E findings across studies could be attributed to differences in genetic methodology, sample design, and measurement of
