In February 2008, Thomas Elbert, a neuropsychologist at Germany’s Universität Konstanz, paid a visit to a man in northern Uganda who had been recruited as a child soldier shortly after the 1994 Rwandan genocide—a bloody ethnic conflict that claimed more than 500,000 lives according to conservative estimates. Elbert watched the man grab a cable lying on the floor, wrap it around his torso like an ammunition belt, wield a piece of scrap metal as if it were an AK-47, and command an empty room to prepare for an attack.
When the man finally emerged from his confused state, he had no understanding or memory of what had just happened. “This man experienced this four or five times a week,” Elbert says. And he’s just one of many.
For the past 3 decades, Elbert has traveled to some of the world’s deadliest war zones—including Somalia, eastern Congo, Sudan, Afghanistan, Iraq, and ...