Self-regulation failures such as aggression typically emerge or worsen around the transition to adolescence. These self-regulation failures come at great cost for individuals, communities, and society at large.

We propose that self-regulation can be improved by addressing something that youth care deeply about: the social norms within their peer group. Here, we will conduct a randomized-controlled trial and follow-up experiments to investigate how changing social norms affects self-regulation and so creates effective behavior change and improved health in youths.
Moreover, we will examine how changes in individual youths cascade into healthier peer networks (e.g., more feelings of safety, less conflicts and bullying, and fewer signs of physical ill-health).