Several small, short-term, or non-experimental studies show that cognitive behavioral-informed trainings reduce antisocial behaviors for 1–2 years. But there is no large-scale, long-term research on persistence. We follow 999 high-risk men in Liberia 10 years after randomization into: 8 weeks of low-cost therapy, $200 cash, both, or a control group. A decade later, men receiving therapy or therapy with cash were about half as likely as the control group to engage in various antisocial behaviors, including robbery, drug-selling, and street fights—far exceeding expert predictions. Impacts are concentrated in the highest-risk men, and most robust from therapy with cash.