PROJECT SUMMARY
During young adulthood, an estimated one in five women experience sexual assault. We 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, we will conduct a RCT comparing
the efficacy of: 1) our 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 a measurement burst design using
electronic daily diaries at baseline and 3, 6, and 9 months post intervention. We 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
our hypotheses are confirmed, results will support the use of our 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.
