People with extremist views aren't only identified by their political, religious, or social beliefs, according to new research.

Those ideological convictions run deep, scientists say – so deep, in fact, that they can be recognised in a 'psychological signature' of cognitive traits and aptitudes that typifies the thinking patterns of the extremist mind.

"There appear to be hidden similarities in the minds of those most willing to take extreme measures to support their ideological doctrines," explains psychologist Leor Zmigrod from the University of Cambridge.

"This psychological signature is novel and should inspire further research on the effect of dogmatism on perceptual decision-making processes," she and colleagues write in their newly published study.

Moreover, it's possible those psychological patterns could be what compels some individuals to adopt strong or radical ideological positions in the first instance, the researchers suggest.

"Subtle difficulties with complex mental processing may subconsciously push people towards extreme doctrines that provide clearer, more defined explanations of the world, making them susceptible to toxic forms of dogmatic and authoritarian ideologies," Zmigrod says.

In the new study, Zmigrod and fellow researchers ran an experiment with 334 participants, who provided demographic information and filled out a series of ideological questionnaires about their personal beliefs, including political, social, and religious beliefs.

In a previous, unrelated study involving the same group of people, the participants had performed an extensive set of 'brain games' tests – cognitive and behavioural tasks on a computer, designed to test things like their working memory, information processing, learning, and mindfulness, among others.

When Zmigrod ran the results from the ideological questionnaires against the cognitive tests, she made a surprising discovery.

"We found that individuals with extremist attitudes tended to perform poorly on complex mental tasks," she explains in The Conversation.

"They struggled to complete psychological tests that require intricate mental steps."

Specifically, those with extremist attitudes – such as endorsing violence against specific groups in society – showed poorer working memory, slower perceptual strategies, and impulsive, sensation-seeking tendencies.

However, the tests didn't only spotlight the traits of extremist thinking – other kinds of ideological beliefs also revealed the shape of their psychological signatures.

Participants who showed dogmatic thinking were slower to accumulate evidence in speeded decision-making tasks, the researchers found, but were also more impulsive and prone to taking ethical risks.

Individuals who were politically conservative showed reduced strategic information processing, heightened response caution in perceptual decision-making paradigms, and displayed an aversion to social risk-taking.

In contrast, participants with liberal beliefs were more likely to adopt faster and less precise perceptual strategies, displaying less caution in cognitive tasks.

Similarly to the conservative group, people with religious views reflected heightened caution and reduced strategic information processing in the cognitive domain, along with enhanced agreeableness, risk perception and aversion to social risk-taking.

"Our research shows our brains hold clues – subtle metaphors, perhaps – for the ideologies we choose to live by and the beliefs we rigidly stick to," Zmigrod explains.

"If our mind tends to react to stimuli with caution, it may also be attracted by cautious and conservative ideologies. If we struggle to process and plan complex action sequences, we may be drawn to more extreme ideologies that simplify the world and our role within it."

Of course, the results here are open to a fair degree of interpretation, and there are limitations to what relatively small psychological studies like this can tell us without further replication involving larger samples.

Nonetheless, the methodology here could lay the groundwork for future psychological tests that may be able to identify individuals at risk of radicalisation and adopting extremist beliefs – as well as suggesting what kind of thinking shields others from the same.

"The [analysis] reveals the ways in which perceptual decision-making strategies can percolate into high-level ideological beliefs, suggesting that a dissection of the cognitive anatomy of ideologies is a productive and illuminating endeavour," the authors write in their study.

"It elucidates both the cognitive vulnerabilities to toxic ideologies as well as the traits that make individuals more intellectually humble, receptive to evidence and ultimately resilient to extremist rhetoric."

The findings are reported in Philosophical Transactions of the Royal Society B.