I agree with the below excerpt, especially the final observation for why many bullying intervention programs are not getting results. Perhaps if we focus our efforts more on the relatively small number of identified bullies while teaching others about how to courageously confront/stand up for victims, we might get better results. The same is true if we can better reach out to parents/families of perpetrators. That is, address the whole school with special attention to the source.
Why are whole-school approaches to reducing bullying relatively ineffective? We contend that anti-bullying programs are struggling for five critical reasons. First, as noted previously, many if not most intervention studies have relied on self-report indices of bullying and victimization, which may not be sufficiently valid and accurate in detecting behavioral change. Second, most anti-bullying programs are not well grounded in a guiding theoretical framework that would inform program development and evaluation. Third, most fail to direct interventions at the social ecology that promotes and sustains bullying perpetration, such as peers and families. Fourth, many of these programs do not address the changing demographics of communities and fail to incorporate factors such as race, disability, and sexual orientation. Finally, schoolwide programs are designed to reach students, when in fact a relatively small percentage of students are directly engaged in bullying perpetration (typically 10%–20% of students are the perpetrators of bullying). Schoolwide programs seldom include direct intervention for the perpetrators, who need to be taught how to engage in prosocial behaviors.
Source: New Perspectives on School Safety and Violence Prevention:
Susan M. Swearer, Dorothy L. Espelage, Tracy Vaillancourt, and Shelley Hymel
What Can Be Done About School Bullying?: Linking Research to Educational Practice
Educational Researcher January 2010 39: 38-47, doi:10.3102/0013189X09357622