Identifying whether GxE effects are sex-specific is a natural extension of this work. In the area of alcohol research, sex-specific G × E effects have not been systematically examined, either in studies of twins or measured genotypes (Salvatore et al., 2017). However, theory and evidence regarding sex differences from disciplines such as psychology, sociology, anthropology, neurobiology, and physiology (including evidence from preclinical research in non-human animals) suggests that there are sex differences in exposures to many of the environments that have been examined in G × E twin studies, including parental monitoring (Barnes et al., 1997, Svensson, 2003), stressful life events (Kessler & Mcleod, 1984), and the health protecting benefits of marriage (Kiecolt-Glaser & Newton, 2001). In one example along these lines, Perry et al. (2013) examined sex-specific G × E effects for GABRA2 as a function of daily hassles (problematic experiences at work and with one’s spouse, children, and friends) and uplifts (pleasurable experiences across the same categories). They found that males who had the high-risk GABRA2 genotype, as indicated by having one or more copies of the A-allele
