Bystanders to Prevent Peer Sexual Violence: Understanding Patterns of Prosocial Behavior Over Time from Early to Later Adolescence.

Programs to prevent peer sexual violence that encourage positive bystander intervention are proliferating. Yet, little is known about how these prosocial behaviors unfold over time across middle to later adolescence. The current study examined helpful bystander actions over three years among students in grades 7-10 (mean age 13.7, range 12-18) at baseline (N = 2539, 53.2% girls). Surveys assessed bystander behavior, social norms, and use of alcohol. Multilevel logistic regression examined patterns of change over time, as well as how changes in attitudes and binge drinking predicted changes in taking bystander action to prevent peer violence. Positive bystander behaviors overall decreased over time, consistent with previous work on bullying. Higher positive social norms and lower denial of sexual violence as a problem were associated with more positive helping behaviors across different waves of data. These findings suggest that the effectiveness of bystander intervention training for peer sexual violence prevention may be enhanced by developing strategies to work against the observed developmental decline in helping, perhaps by social marketing campaigns that can bolster positive social norms.