Another issue for these models relates to possible gender effects. This could be salient because males are more likely to have higher impulsivity, itself a risk factor for heavy drinking. Also, while both sons and daughters of alcoholics demonstrate lower LRs than matched family-negative controls overall, females are likely to weigh less and have lower muscle mass with a higher BAC (Chung and Martin, 2009; Eng et al., 2005; Sher et al., 2005). Despite these differences, evaluations through invariance procedures of whether it was reasonable to combine males and females in prior models revealed few significant gender differences (Schuckit et al., 2008a, 2008c, 2009a). However, lack of statistical differences between males and females in the model (i.e., invariance) could reflect insufficient statistical power and a more definitive answer to gender effects requires a larger sample.
