Psychologist Jeremy Ginges of the New School for Social Research in New York City and anthropologist Scott Atran of the National Centre for Scientific Research in Paris, France, presented 50 US students with a hypothetical crisis in which a foreign country captured 100 US citizens and was expected to kill them. Half the volunteers were asked to consider a military response to the kidnapping, and half a diplomatic response.

When told that their action would result in all hostages being saved, both groups endorsed the plan presented to them. Told that one hostage would die, however, most “diplomats” became reluctant to endorse the proposed response. “Militarists” had no such qualms. In fact, the most common response suggested that they would support military action even if 99 hostages died as a consequence. Similar results were found in studies of Nigerian and Palestinian volunteers.

“People are much more willing to accept grievous losses during violence than in diplomacy,” Atran says. “It doesn’t make any sense.”