2 Two-Pyramids Model of Radicalization to Terrorism

This chapter reviews the origins and developments of the Two-Pyramids Model of radicalization, which distinguishes between the radicalization of opinions and the radicalization of actions. The Radicalization of Action Pyramid categorizes individuals from passive (inert) to those committing terrorist acts, while the Radicalization of Opinion Pyramid progresses from neutrality to a personal moral obligation to act violently for a cause. Empirical studies, including the Activism and Radicalism Intention Scales (ARIS), support the model’s distinction between activism and radicalism as separate dimensions. The chapter highlights the importance of group dynamics, diagnostic and prognostic frames, and the role of public opinion in shaping political violence. Security and policy implications include promoting non-violent activism and addressing grievances without reinforcing extremist narratives, and a call for more attention to perceptions of mass opinion as a normative power that can encourage or discourage political violence.