Friction: How Conflict Radicalizes Them and UsTerrorism is an extreme form of radicalization. In this ground breaking and important book, Clark McCauley and Sophia Moskalenko identify and outline twelve mechanisms of political radicalization that can move individuals, groups, and the masses to increased sympathy and support for political violence. Co authored by two psychologists both acknowledged in their field as experts in radicalization and consultants to the Department of Homeland Security