We conducted a systematic review of the contemporary scientific literature to (a) identify consensus, where it exists, regarding factors associated with membership in terrorist organizations and/or perpetration of terrorist attacks; (b) drive future research directions; and (c) inform evidence-based counterterrorism strategies. Systematic searches of 6 databases identified 205 articles that met inclusion criteria. Of these, 50 articles reported on findings of empirical research, 24 reported inferential statistics, and 6 of these compared characteristics of known terrorists to nonterrorists. Across various aspects of terrorism and terrorists (e.g., type of terrorist, attack type), articles rarely specified their focus. When examined factors typically focused on characteristics of the individual. Review of the empirical findings suggest 9 variables with at least some support for their association with terrorism: age, socioeconomic status, prior arrest, education, employment, relationship status, having a grievance, geographic locale, and type of geographic area. However, given the limitations of the research, there is insufficient evidence to conclude that any of these variables are empirically supported risk factors. Findings identified additional characteristics of an individual (i.e., country of birth, Islamic faith, military experience, foreign travel history, family or friend in a terrorist or extremist organization) and their environment (i.e., income inequality, media and government influences) that merit further evaluation. Findings also emphasized the importance of a triggering event. Finally, findings indicate that some widely accepted "risk" factors have limited empirical support for their association with terrorism. A focus on these factors might contribute to discrimination and reduce the effectiveness of counterterrorism strategies.

No abstract

There has been relatively limited empirical investigation of the characteristics and activities of women involved in jihadism-inspired terrorism. To address this knowledge gap, we describe demographic characteristics, criminal history, organizational involvement, plot involvement, and foreign fighting of 405 women involved in jihadisminspired terrorism. We also perform comparative analyses with a subgroup of women (n ϭ 272) matched to a sample of male terrorists (n ϭ 266). Women involved in jihadism-inspired terrorism were diverse in their ethnicities and countries of citizenship; the majority were legal, native residents of their countries. Most had completed at least high school; about half had no recent employment. Women rarely had criminal histories. Most women were linked to at least one terrorist organization, but were not often involved in plots. About half of the women attempted to engage in foreign fighting. Compared to men, women were more often born in 1990 or later, more likely to have no recent profession, and had significantly fewer crimes prior to radicalization. We found no differences on education or criminal activity after radicalization. Compared to men, women were more often associated with at least one organization and less likely to be involved in plots. Women were more likely to attempt foreign fighting at least once and were more often successful on their first attempt. We did not find differences on age of radicalization or age of first foreign fighting attempt. Implications for research, policy, and practice include the need for gender-informed theories of radicalization, threat assessment, and other counterterrorism strategies. Public Significance StatementThe present study reveals differences in the backgrounds of women and men involved in jihadism-inspired terrorism, suggesting different pathways into terrorism. We further find differences in women's and men's terrorism-related outcomes, demonstrating that some types of terrorist activity are likely to vary by gender.

No abstract