Initiative Description: Meta-analysis of school-based programs for preventing or reducing aggressive behavior. 221 studies were described in 362 written reports. The time interval between pretest and posttest ranged widely from less than 6 weeks to more than a full school year, with a median of about 17 weeks. The most common program delivery personnel were teachers and researchers.

Study Results: Higher risk youth showed greater reductions in aggressive behavior,

Reference: Wilson, S. J., Lipsey, M. W., & Derzon, J. H. (2003). The effects of school-based intervention programs on aggressive behavior: A meta-analysis. Journal of Consulting and Clinical Psychology, 71(1), 136–149. https://doi.org/10.1037/0022-006X.71.1.136

Level of Evidence: Very Good