New studies explore why ordinary people turn terrorist

Research in the Iraqi war zone point to key characteristics among ISIS soldiers and their opponents

group of ISIS members

DEADLY DEVOTION  A collective sense of identity plus deeply held values may inspire Islamic State supporters, such as those shown here, to sacrifice everything for their cause.

Tauseef Mustafa/AFP/Getty Images

Fierce combat erupted in February 2016 at the northern Iraqi village of Kudilah.