A false dichotomy? Mental illness and lone-actor terrorism.

Area of Science:

• Psychology
• Criminology
• Sociology

Background:

• Understanding the psychological profiles of terrorists is crucial for developing effective counter-terrorism strategies.
• Distinguishing between lone-actor and group-based terrorism is essential due to differing operational methods and motivations.
• Previous research has explored mental illness in terrorism, but a direct comparison with a matched sample of group actors is limited.

Purpose of the Study:

• To investigate the prevalence of mental illness in lone-actor terrorists compared to group-based terrorists.
• To identify behavioral differences between lone-actor terrorists with and without mental illness.
• To provide actionable insights for security agencies in monitoring and preventing lone-actor terrorist events.

Main Methods:

• Utilized a unique dataset of 119 lone-actor terrorists and a matched sample of group-based terrorists.
• Conducted bivariate, multivariate, and multinomial statistical analyses.
• Stratified the sample across various diagnoses to test for distinct differences.

Main Results:

• Lone-actor terrorists were 13.49 times more likely to have a mental illness than group-based terrorists.
• Mentally ill lone actors were 18.07 times more likely to have a partner involved in a wider movement.
• Individuals with mental illness reported more proximate life changes, recent victimization due to prejudice, and experienced chronic stress.

Conclusions:

• Mental illness is a significant factor differentiating lone-actor from group-based terrorists.
• Specific behavioral correlates associated with mental illness in lone actors can inform risk assessment.
• A multivariate approach is necessary for a comprehensive understanding of lone-actor terrorism.