A Meta-Analytic Review of the Relationship Between Alcohol and Bystander Intervention for Sexual Assault.

Sexual assault (SA) remains a significant public health issue, and there is growing interest in SA prevention approaches. Bystander intervention (BI) programs aimed at increasing individuals' willingness to intervene when they witness problematic situations show promise. However, social contexts that are high-risk for SA often involve alcohol, which may impact bystanders' abilities to intervene. Indeed, theoretical and empirical work has suggested that alcohol may impact BI. However, research has yet to quantitatively and systematically review extant literature to quantify whether and how much alcohol might impair BI. The current meta-analysis estimated associations between bystander alcohol use and BI in real, imagined, or hypothetical SA scenarios within both experimental and correlational/naturalistic studies, disaggregating the latter into BI behaviors, intentions, and attitudes. Database searches and author requests yielded 27 eligible articles ( = 11,139) for meta-analysis. Results suggested that naturalistic alcohol use (i.e., alcohol use as it occurs across daily life) may be negatively correlated with bystander intentions only ( = 15,  = -.08,  < .001). Experimentally administered alcohol may also be negatively associated with BI ( = 5,  = -0.16,  = .002), but this association was less robust and appeared specific to attitudes. Moderation analyses suggested that such patterns might shift as a function of college status but not gender. Samples with outlying effect sizes and the relatively low number of experimental studies identified indicate the need for more research in this area. These findings thus inform the next steps for research in this area and for refinement of bystander-based interventions to be optimally effective in reducing SA risk.