Importantly, there is evidence indicating experiences of sexual assault during these two life phases are related, as victimization and perpetration during adolescence are, respectively, associated with increased risk of victimization and perpetration during young adulthood (Cui, Ueno, Gordon, & Fincham, 2013). Thus, early prevention efforts are of paramount importance. Reviews of research on the effectiveness of programs designed to prevent sexual assault among adolescents and college students have noted both a dearth of high-quality studies, such as randomized controlled trials (RCTs), and minimal evidence that these prevention programs have meaningful effects on young people's behavior (DeGue, Valle, Holt, Massetti, Matjasko, & Tharp, 2014; De Koker, Mathews, Zuch, Bastien, & Mason-Jones, 2014). Concerning the latter point, evaluations of such programs tend to measure attitudinal outcomes (e.g., rape supportive attitudes, rape myth acceptance) more frequently than behavioral outcomes (e.g., perpetration or victimization) (Anderson & Whiston, 2005; Cornelius & Resseguie, 2007; DeGue et al., 2014). Additionally, findings from a metaanalysis of studies assessing outcomes of college sexual assault prevention programs suggested that effects are larger for attitudinal outcomes than for the actual incidence of sexual assault (Anderson & Whiston, 2005). The Bystander Approach Given this paucity of evidence of behavior change, it is imperative that researchers identify effective strategies for preventing sexual assault among adolescents and young adults. One promising strategy is the implementation of bystander programs, which encourage young people to intervene when witnessing incidents or warning signs of sexual assault. The strength of the bystander model lies in its emphasis on the role of peers in the prevention of violence. Peers are a salient influence on young people's intimate relationships (Adelman & Kil, 2007; Giordano, 2003). In some respects, this can be detrimental, as having friends involved in violent intimate relationships (i.e., characterized by sexual or physical violence)