As we learned in last week’s episode, a simple and inexpensive program to reduce crime in Chicago has had remarkable results. At-risk teenagers who undergo a short series of Cognitive Behavioral Therapy (CBT) sessions are less likely to get arrested and more likely to stay in school.

But could CBT also help criminals well into their adulthood? How about if their history of violence goes back to their time as child soldiers in a gruesome civil war? In this episode, we explore that seemingly unlikely proposition — along with a few other scenarios in which behavioral therapy seems to work well.

By the end of Liberia’s two civil wars, nearly 10 percent of the population had been killed, and thousands of child soldiers were now men. Many of them couldn’t shake the violent behaviors they had learned in wartime. “The war was a form of virus,” Bohr laments.We hear from Klubosumo Johnson Borh, who as a Liberian teenager was recruited into Charles Taylor‘s notoriously brutal rebel army. Borh was made a commander, overseeing fighters who were even younger than him. “Child soldiers were always used … to torture,” Bohr says. “Even if there was a case wherein such a person needed to be executed, you always would want to use child soldiers to do that.”

Years after the war, Borh helped start an organization called the Network for Empowerment and Progressive Initiative (NEPI) to help former soldiers and other young men who were in trouble or heading for trouble.

As NEPI began to see results, Bohr began collaborating with Chris Blattman, a Columbia University economist and political scientist. Blattman wanted to see for himself exactly what NEPI was doing. What he found was that NEPI had accidentally stumbled upon CBT. It was teaching young men anger management and self-control, using the same kind of therapeutic and role-playing exercises used by other CBT programs like Becoming a Man, the Chicago program wediscussed last week.

One element that Blattman (and his colleagues Julian C. Jamison and Margaret Sheridan) added to the Liberia intervention was a cash incentive — specifically $200, which goes a long way in Liberia, where the gross national income per capita is $400.

Blattman and Bohr conducted a randomized control trial of 1,000 men in Monrovia, Liberia’s capital, dividing them into four groups: those who received 1. just cash; 2. just CBT; 3. cash plus CBT; and 4. no intervention at all (the control group). Criminal behavior fell substantially in all groups receiving an intervention but after a year, it was those who got both CBT and cash who were still staying out of trouble. “All of these things we call antisocial behaviors like aggression, and cheating, and things of this nature, and everyday violence, those were still down a lot, by about 40 or 50 percent in the groups that received both cash and therapy,” Blattman tells us. (He and his colleagues published their results in a paper called “Reducing Crime and Violence: Experimental Evidence on Adult Noncognitive Investments in Liberia.”)

Between the evidence from Liberia and Chicago, there is mounting evidence that CBT has the potential to be a solution to all sorts of problems that have traditionally proven difficult (and expensive) to fight. And there is further evidence from coastal England. In this episode, we meet Heather Strang, research director at Cambridge University’s Institute of Criminology. She has been studying a program that fights domestic violence. By directing low-level offenders into just two behavioral-therapy workshops, the program achieves a 40 percent reduction in repeat incidents. As one abuse victim reported, “I don’t know what you’ve done with my husband but he’s a changed man.”

We also speak with Simon Ruda, of the Behavioral Insights Team, a quasi-governmental unit based in London that applies behavioral-science findings to public policy—everything from tax collection to crime prevention. (It also known as the Nudge Unit, after the book Nudge  by  Richard Thaler and Cass Sunstein.)

And we revisit Walter Mischel‘s famous marshmallow test, and ponder a related question: would a simple, handwritten message on a holding cell wall deter its occupant from committing more crimes?

In the end, Stephen Dubnerposits that all these results may suggest that the way we think about crime and punishment generally is perhaps wildly, hopelessly outdated. That maybe, for criminals who tend to be written off as lost causes, there is an alternative. “There’s been an assumption that adults are no longer malleable,” Chris Blattman says, “and we need to throw adults under the bus and put all our social spending into preschoolers to have a better future generation rather than say these guys can actually change.”