Is radicalization a family issue? A systematic review of family‐related risk and protective factors, consequences, and interventions against radicalization

Background Family‐related risk and protective factors are crucial for different antisocial behaviors, but their role in radicalization requires synthesis. Radicalization is likely to have a negative impact on families, and well‐designed and implemented family‐focused intervention programs have the potential to decrease radicalization. Objectives Research questions were: (1) What are the family‐related risk and protective factors for radicalization? (2) What is the impact of radicalization on families? (3) Are family‐based interventions against radicalization effective? Search Methods Searches included 25 databases and hand searches of gray literature from April to July 2021. Leading researchers in the field were asked to provide published and unpublished studies on the topic. Reference lists of the included studies and previously published systematic reviews on risk and protective factors for radicalization were scanned. Selection Criteria Published and unpublished quantitative studies on family‐related risk and protective factors for radicalization, the impact of radicalization on families, and family‐focused interventions were eligible with no restrictions regarding the study year, location, or any demographic characteristic. Studies were included if they measured the relation between a family‐related factor and radicalization or if they included a family‐focused intervention against radicalization. For family‐related risk and protective factors, radicalized individuals needed to be compared to general population. Studies were included if they defined radicalization as support or commission of violence to defend a cause, including support for radical groups. Data Collection and Analysis The systematic search identified 86,591 studies. After screening, 33 studies focused on family‐related risk and protective factors were included, with 89 primary effect sizes and 48 variables grouped in 14 factors. For the factors that included two or more studies, meta‐analyses with random effects were conducted. When possible, moderator analyses were performed together with sensitivity and publication bias analyses. No studies on the impact of radicalization on families or family‐focused interventions were included. Results The current systematic review based on studies with 148,081 adults and adolescents from diverse geographic locations showed that parental ethnic socialization (z = 0.27), having extremist family members (z = 0.26), and family conflict (z = 0.11) were related to more radicalization, whereas high family socioeconomic status (z = −0.03), bigger family size (z = −0.05), and high family commitment (z = −0.06) were related to less radicalization. Separate analyses described family‐factors for behavioral versus cognitive radicalization, and different radical ideologies including Islamist, right‐wing and left‐wing. It was not possible to distinguish risk and protective factors from correlates and the level of overall bias was mostly high. No results regarding the impact of radicalization on families or family‐focused interventions were included. Authors' Conclusions Although causal relations between family‐related risk and protective factors could not be established, it is reasonable to suggest that policies and practice should aim at decreasing family‐related risks and increasing protective factors for radicalization. Tailored interventions including these factors should be urgently designed, implemented and evaluated. Studies focused on the impact of radicalization on families and family‐focused interventions are urgently needed together with longitudinal studies on family‐related risk and protective factors.