genetic influences are shared (rG=0.35). Notably, previous work has found limited evidence for genetic influences on EAU and instead exclusively highlighted the role of unique and shared environmental factors (Richmond-Rakerd et al., 2014). Alternatively, results from the current study, which did not include opposite-sex pairs or unpaired twins, are consistent with research demonstrating that both EAU (heritability=.36; Young-Wolff et al. 2012) and NSSI (heritability=.59 for women and .37 for men; Maciejewski et al. 2014) are partially influenced by genetic factors. One plausible explanation for these results is that this shared genetic liability may reflect vulnerability to other forms of psychopathology, such as borderline personality disorder, or to dispositional risk factors not assessed in the current study, namely disinhibition or negative urgency, a facet of impulsivity that manifests as a tendency to engage in rash behavior when experiencing negative emotions (Whiteside and Lynam 2003). For example, Squeglia and colleagues (2014) have demonstrated that poor inhibitory control predicts early adolescent transition to alcohol use. Self-reported impulsivity, and more specifically negative urgency, has also been linked to self-harm (Hamza et al. 2015), although these findings do not translate to laboratory-based measures of impulsivity. Therefore, future research should examine whether the association between EAU
