Social Movement Theory Perspectives On Group Mobilisation, Radicalisation, And Violent Extremism. A Rapid Evidence Assessment

By NADINE SALMAN , SARAH MARSDEN , JAMES LEWIS

This report synthesises and critically analyses the existing research that has considered whether and how political contention and protest relate to radicalisation and terrorism. It draws on social movement theory perspectives to provide insights into what informs group and mass radicalisation and what constrains them, and what impact state responses have. AIMS This review seeks to address the following primary research questions: 1. What factors, features, or events are linked to violence, radicalisation, and terrorism in social movements? 2. What factors, features, or events constrain the potential for violence, radicalisation, and terrorism in social movements? 3. What are the mechanisms that help explain what facilitates or constrains opportunities for violence in social movements? 4. How do different state and policing responses affect the potential for violence and extremism in social movements? METHODOLOGY This research adopts a rapid evidence assessment (REA) approach, synthesising knowledge on specific topics in line with the research questions from KEY FINDINGS This REA identifies several potential drivers for violent and extremist escalation within social movements, as well as potential factors for de-escalation. The literature reviewed highlights the complex and interacting nature of movement characteristics, mobilisation contexts, and the influence of external actors, namely countermovements and state responses. Key findings identified in this review are summarised in a table for each major section, loosely based on the EMMIE framework for evidence relating to crime prevention interventions (Johnson et al., 2015). The EMMIE framework summarises the overall effect, direction, and strength of the evidence;1 the mechanisms or mediators it activates; relevant moderators or contexts, including unintended effects; implementation considerations; and economic costs/benefits (Johnson et al., 2015). Since the findings of this review are not solely concerned with interventions, the latter two considerations are not summarised here. These tables therefore highlight the factors identified, their overall effects on violence and/or extremism, any identified mechanisms and/or moderators, and the strength of the evidence from the literature base. Movements are informed by their socio-historical contexts and internal dynamics, the factors set out in the tables therefore represent general trends in the research rather than firm indicators of movement behaviour. The effects identified below should not, therefore, be interpreted as suggesting a direct causal relationship between a given factor and the likelihood of violence/ extremism, but instead as evidence of how these factors have impacted the dynamics within certain contexts and mobilisations. MOVEMENT CHARACTERISTICS Different movement characteristics, including factors relating to movement structure, resources, and composition, as well as ideological factors, may contribute to an increased potential for engaging in or rejecting violence. Understanding the characteristics of a given movement is therefore an important first step when understanding how and why violence is produced.

Department of Psychology, Lancaster University, Lancaster, LA1 4YF, UK.The Centre for Research and Evidence on Security Threats (CREST), 2025. 44p.