Radicalization into Violent Extremism I: A Review of Social Science Theories

In discourse about countering terrorism, the term "radicalization" is widely used, but remains poorly defined. To focus narrowly on ideological radicalization risks implying that radical beliefs are a proxy—or at least a necessary precursor—for terrorism, though we know this not to be true. Different pathways and mechanisms of terrorism involvement operate in different ways for different people at different points in time and perhaps in different contexts. This article explores the problems in defining radicalization and radicalism, and suggests that radicalization—and more specifically, involvement in terrorism—might best be viewed as a set of diverse processes. It goes on to review several potentially promising theories that might support further study of those processes, including social movement theory, social psychology, and conversion theory. Finally, it describes some possible frameworks for understanding how the processes might facilitate terrorism-related behavior.