Research at Keele University has examined why members of the public make judgements as to whether violent attackers are viewed as either terrorists or mentally ill, and have found that it goes beyond the usual stereotyping.

In a series of studies, Dr Masi Noor, a Social Psychologist at Keele University, and his co-authors examined how people judge and label a violent attacker. The study found that when a person shares the same broad political beliefs as an attacker, people would feel motivated to protect their position by explaining away the violent behaviour. In particular, the researchers found that people who shared a similar political stance with a violent attacker tended to attribute the attacker a more exonerating motive, such as mental illness, rather than a terrorist motive.

The researchers conducted their first study on the day of the Brexit referendum in Britain, a week after Thomas Mair had killed the MP and strong supporter of the ‘Remain’ campaign, Jo Cox. The researchers surveyed 200 British participants about their preferred referendum outcome and on Mair’s motivation in killing Mrs Cox, before his true motive was public knowledge. The survey found that ‘Leave’ supporters - who knew Mair would be grouped with them if his motivations were found to be political- were more likely to view Mair as mentally ill. By contrast, ‘Remain’ supporters were more likely to label Mair as a terrorist.

A second study showed a similar pattern. German participants were surveyed shortly after a Syrian refugee committed suicide and injured 15 people at a German festival in 2016. Participants who identified themselves as pro-immigration were more likely to say the suicide bomber was mentally ill, whereas those who self-identified as anti-immigration were more likely to call the same individual a terrorist.

In the final study, the researchers investigated what happens when a perpetrator’s motive is obvious, therefore allowing little room for interpretation. The researchers surveyed about 500 people who identified themselves as American. The study revealed that participants were more likely to distance an attacker with a clear political motive from being American by assuming that the attacker was of non-American and Muslim origins, as compared to when the attacker’s motive was described relating to mental illness. This pattern of results was most pronounced for participants who had a high level of American identification.

Dr Noor said: “Across all three studies, we found that attributing a mental illness (vs. terrorist) motive bore important consequences for the violent individuals and their groups: participants were likely to assign a more lenient punishment to perpetrators (and their groups if the perpetrator had died in the incident) with a mental illness motive than perpetrators with a terrorist motive.

“By their own nature motives rely on our inferences and assumptions. Our research demonstrates that as perceivers we are invested in our social environments and rather protective of the group identities we cherish. Precisely for this reason, we systematically process social information in a self- and group-serving manner. Our research calls on the media, politicians, judges, and other community leaders to bear such biases in mind when passing judgements on individuals and their respective groups.”