This article conceptualizes political radicalization as a dimension of increasing extremity of beliefs, feelings, and behaviors in support of intergroup conflict and violence. Across individuals, groups, and mass publics, twelve mechanisms of radicalization are distinguished. For ten of these mechanisms, radicalization occurs in a context of group identification and reaction to perceived threat to the ingroup. The variety and strength of reactive mechanisms point to the need to understand radicalization—including the extremes of terrorism—as emerging more from the dynamics of intergroup conflict than from the vicissitudes of individual psychology.
McCauley, Clark, and Sophia Moskalenko. 2008. "Mechanisms of Political Radicalization: Pathways Toward Terrorism." Terrorism and Political Violence 20 (July): 415-433. http://www.tandfonline.com/doi/abs/10.1080/09546550802073367#preview