Who will help prevent sexual violence: Creating an ecological model of bystander intervention.

Given the prevalence of sexual and relationship violence in communities, innovations in prevention are sought. One promising line of inquiry directs efforts not at victims or perpetrators but at community members who are potential witnesses to high-risk events along the continuum of violence or who may need to support victims after an assault. To date, the main organizing framework for understanding bystander behavior is the work of Latane and Darley (1970), who described a series of stages that lead to an individual's decision to intervene or not when someone needs help. Yet this model focuses mainly on factors within the individual or his or her immediate context. In the current review, I use ecological models by Bronfenbrenner (1977, 2005) and Kelly (2006) to expand our view of key factors that help promote and may serve as barriers to helpful bystander intervention. For example, ecological theories suggest important community-level variables, such as campus size or cultural values, that may influence the degree of helping and may, in some instances, be leverage points for creating change.