“Over 20 databases were searched for both published and gray literature. In order to provide a more comprehensive review, supplementary searches were conducted in two German and one Dutch database,” according to the study.
“Reference harvesting was conducted from previous reviews and contact was made with leading researchers to identify and acquire missing or unpublished studies.”
As part of the study, researchers grouped the factors into five domains: socio-demographic and background factors, psychological and personality trait factors, attitudinal and subjective belief-related factors, experiential factors, and traditional criminogenic factors.
The vast majority of the study examined either represented no particular radicalized ideology or only focused on particular ideologies, such as far-right, far-left, and Islamic radicalization.
“The studies generally demonstrated low risk of bias and utilized validated or widely acceptable measures for both indicators and outcomes. With some exceptions, sociodemographic factors tend to have the smallest estimates, with larger estimates for experiential and attitudinal factors, followed by traditional criminogenic and psychological factors,” the study found.
“While risk assessment and counter-radicalization take a risk-protective factor approach, there is widespread debate as to what these factors are and which are most important.”