RCT of a Combined MI Intervention to Address Bystander Behaviors in the Context of Alcohol Use

During young adulthood, an estimated one in five women experience sexual assault. The investigators seek to reduce this violence by motivating young adults to intervene with their peers to prevent sexual assault-an approach known as bystander intervention. Current bystander training is conducted in group sessions involving education about how to recognize and intervene in response to sexual risk situations. Although successful in changing knowledge and attitudes about sexual assault prevention, evaluations of these programs have rarely focused on changing actual bystander behaviors. Further, while bystander alcohol use is common in sexual risk situations, and undermines intervention attempts, alcohol consumption by bystanders is not explicitly targeted in existing intervention training programs. To address these gaps, the investigators will conduct a RCT comparing the efficacy of: 1) the recently developed bystander intervention, Motivate-the-Bystander (MTB), 2) MTB with an MI alcohol component (MTB+ALC), and 3) an attention control condition for reducing alcohol use and increasing bystander behaviors in response to sexual risk. Bystander behaviors will be assessed observationally during a virtual reality-based house party at 2 months post intervention. Participants' bystander behaviors, alcohol use, and relevant contextual variables will be assessed with an EMA measurement design using electronic daily diaries at baseline and weekly post intervention until month 9. The investigators expect that, compared to MTB alone and the control condition, MTB+ALC will produce significantly greater reductions in overall drinking and increases in prosocial bystander behaviors in a diverse sample of 450 young adults who are heavy drinkers. If the hypotheses are confirmed, results will support use of the combined MI-based bystander-alcohol intervention as an effective means of reducing drinking and motivating bystander behaviors among those at highest risk for sexual violence.