The Base Rate Study: Developing Base Rates for Risk Factors and Indicators for Engagement in Violent Extremism

Abstract

Improvements have been made in identifying the prevalence of risk factors/indicators for violent extremism. A consistent problem is the lack of base rates. How to develop base rates is of equal concern. This study has two aims: (i) compare two methods for developing base rates; the Unmatched Count Technique (UCT) and direct questioning, (ii) generate base rates in a general population sample and compare these to a sample of lone-actor terrorists (n = 125). We surveyed 2108 subjects from the general population. Participants were recruited from an online access panel and randomly assigned to one of three conditions; direct survey, control, or UCT. Survey items were based on a loneactor terrorist codebook developed from the wider literature. Direct questioning was more suitable under our study conditions where UCT resulted in deflation effects. Comparing the base rates identified a number of significant differences: (i) lone-actor terrorists demonstrated propensity indicators related to a cognitive susceptibility, and a crime-and/or violence-supportive morality more often; the general sample demonstrated protective factors more often, (ii) lone-actor terrorists demonstrated situational indicators related to a crime-and/or violence-supportive morality more often, whereas the general sample experienced situational stressors more often, (iii) lone-actor terrorists demonstrated indicators related to exposure to extremism more often. Results suggest there are measurable differences in the prevalence of risk factors between lone-actor terrorists and the general population. However, no single factor "predicts" violent extremism. This bears implications for our understanding of the interrelation of risk and protective factors, and for the risk assessment of violent extremism.

Similar crimes, similar behaviors? Comparing lone‐actor terrorists and public mass murderers

“…This article adds to the growth in data‐driven analyses comparing samples of violent extremists with other violent populations of interest [39]. The results demonstrate that many major potential risk factors (e.g., existing mental disorders) are just as common among and between lone‐actor terrorists and mass murderers.…”

The Culture of Violent Talk: An Interpretive Approach

“…From an evolutionary perspective, human survival demands the assessment of threat (Flannelly et al 2007). In an age where terrorism generates the level of concern that it does today, threat assessment considerations have taken on an even greater prominence (Clemmow et al 2020;Logan and Lloyd 2019). In the United States, for example, an entire industry of threat assessment offers advice to employers, schools, and a variety of other social institutions about detecting potential perpetrators (Mueller 2010).…”

Hidden order across online extremist movements can be disrupted by nudging collective chemistry

“…We show how actions by social media platforms could disrupt the onset and 'flatten the curve' of such online extremism by nudging its collective chemistry. Our results provide a system-level understanding of the emergence of extremist movements that yields fresh insight into their evolution and possible interventions to limit their growth.Online extremism often develops into offline violence [1][2][3][4][5] . The crowd that stormed the U.S. Capitol Building in January 2021 included members of extremist groups that use social media to coordinate activities, including members of the Boogaloo movement studied here 6 .…”

“…New strategies are therefore needed to complement these existing tools.This paper provides a quantitative study of the emergence of such movements online: in particular, we study how the groups of online supporters emerge and grow over time (Figs. 1,2,3,4,5). We purposely take a…”

“…Online extremism often develops into offline violence [1][2][3][4][5] . The crowd that stormed the U.S. Capitol Building in January 2021 included members of extremist groups that use social media to coordinate activities, including members of the Boogaloo movement studied here 6 .…”