We show self control and self image are malleable in adults, and that investments in them reduce crime and violence. We recruited criminally-engaged Liberian men and randomized half to eight weeks of group cognitive behavioral therapy, teaching self control skills and a noncriminal self-image. We also randomized $200 grants. Cash raised incomes and reduced crime in the short-run but effects dissipated within a year. Therapy increased self control and noncriminal values, and acts of crime and violence fell 20–50%. Therapy’s impacts lasted at least a year when followed by cash, likely because cash reinforced behavioral changes via prolonged practice.
Blattman, C. Reducing crime and violence: Experimental evidence on adult noncognitive investments in Liberia. (2015) 76 pp.