When Helping Hurts? Toward a Nuanced Interpretation of Adverse Effects in Gang-Focused Interventions

We examined gang interventions that produced adverse effects, or worse outcomes for treated participants in controlled evaluations. Prior studies describe harmful psychological processes and flawed research methods that can cause adverse effects in gang and crime prevention programs. We tested whether several program elements and methodological issues predicted adverse effects across 41 controlled evaluations. Only the presence of law enforcement officers as intervention providers significantly predicted adverse outcomes, and it is unclear whether law enforcement officers increased participants' antisocial behaviors or simply detected more offending among treated participants. Including law enforcement officers in gang interventions may increase the risk of adverse outcomes; however, further research is needed to determine why. Public Health Significance StatementInterventions to reduce delinquency and gang involvement should at least do no harm. However, practitioners and researchers must be cautious when interpreting what appear to be harmful effects. Methodological problems with program evaluation can produce outcomes that favor control participants, even if programs are not harmful.