Psychosocial Prevention Programs against Radicalization and Extremism: A Meta-Analysis of Outcome Evaluations

Politically, religiously, and otherwise motivated radicalization and violent extremism is a topic of high priority in many countries. Therefore, beyond intelligence and police measures, there is a strong increase of psychosocial prevention programs in this field. However, little is known about their effectiveness. We aimed to fill this research gap by conducting a systematic international review and meta-analysis of outcome evaluations. We screened about 14,000 reports on the topic of extremism prevention, but in spite of broad criteria of eligibility, we only found nine more or less well-controlled outcome evaluations from seven countries. Six programs addressed religious/ethnic extremism, one targeted nationalist/separatist extremism, and one different types of extremism. Most evaluations had a quasi-experimental pre-post design, only one contained a randomized controlled trial (RCT). Overall, programs had a significant mean positive effect on behavioral and psychosocial outcomes related to extremism (d = 0.50, SE = 0.12). Regarding the specific effects of the programs on psychosocial aspects such as for example extremist attitudes alone, we found similar results (d = 0.56, SE = 0.11). We found stronger effects for programs with target groups from mixed ethnic backgrounds and approaches addressing both at-risk individuals and participants from the general population. Despite these promising results, the low internal validity of most evaluations and small number of eligible studies limit generalization. More high-quality evaluations are clearly needed. These would help to allocate resources in an evidence-oriented manner and provide a better understanding of the mechanisms of successfully preventing radicalization and violent extremism.