Trauma, Adversity & Violent Extremism: A Systematic Review

By James Lewis, Sarah Marsden, Jmes Hewitt and Anne Peterscheck 

This report presents the findings of a systematic review of research on how, and under what circumstances, trauma might be implicated in individual journeys into, and out of, violent extremism. It builds on previous work carried out by the research team on these dynamics, including a scoping review of the literature (Lewis & Marsden, 2021), and a process of network development involving a series of workshops bringing together researchers, policymakers and practitioners to discuss the relevance of trauma and adversity to violent extremism. This process confirmed there was a nascent, but growing, body of research exploring this topic, and that there was significant practical and analytical utility in exploring these processes in greater depth. 
The analysis presented in this report develops this research programme in three ways:

1. Undertaking a systematic review of post-2000 empirical, academic research on trauma, adversity and violent extremism to better understand a) the prevalence of trauma in the life histories of violent extremists; and b) the relevance of trauma in interpreting pathways towards, and away from, violent extremism.

2. Examining the different ways in which trauma is implicated in radicalisation pathways by synthesising this research on trauma, adversity and violent extremism with radicalisation models identified in a separate systematic review. 

3. Exploring how applying a trauma-informed perspective to understanding journeys into and out of violent extremism might inform research and practice.

Overview of the Report

This report consists of eight sections. The next section provides an overview of the key concepts discussed in the report, before discussing the conceptual framework that underpins our analysis. This is followed by an overview of our methodology and by three analysis sections addressing the three objectives outlined above:

1. Section one sets out the evidence identified through the systematic review. Drawing on 159 studies, it discusses the different relationships that have been identified between trauma, adversity and violent extremism. 

2. The second section explores whether and how trauma is captured in existing radicalisation models. This draws on an analysis of 99 papers identified through a separate systematic review of radicalisation models (Corner & Taylor, 2023). 

3. The final section presents a more theoretical and conceptual analysis, reviewing the implications of these findings for research and practice. 

The report concludes by summarising the key conclusions, implications, and recommendations for researchers, policymakers, and practitioners.

Lancaster, UK:  Centre for Research and Evidence on Security Threats  - CREST, 2024.