People who gravitate towards extremism and simplistic worldviews do so because they literally don't have the cognitive ability to process complex information, a new study has found.
Researchers in the UK surveyed hundreds of Americans, asking them about their views on political matters - such as religion, authority, patriotism, economics, abortion, equality and so on - as well as testing their cognition.
They found strong links between how a person interprets information, and how they see the world.
Conservatives, for example, when asked to answer quickly and accurately, took longer than liberals to respond - but tended to have more accuracy.
"It’s fascinating, because conservatism is almost a synonym for caution,” lead author Leor Zmigrod of the University of Cambridge told The Guardian.
"We're seeing that - at the very basic neuropsychological level - individuals who are politically conservative… simply treat every stimuli that they encounter with caution."
Those whom the surveys outed as 'dogmatic' - stuck in their ways, regardless of the evidence - also took longer to process information.
"Conservatism and nationalism were related to greater caution in perceptual decision-making tasks and to reduced strategic information processing, while dogmatism was associated with slower evidence accumulation and impulsive tendencies," the study said - in other words, they're slower than others to figure out what's happening, but unfortunately quicker to act.
"Dogmatic individuals may possess reduced inhibition that could be compounded by slower information uptake, leading to impulsive decisions based on imperfectly processed evidence."
Conservatism and nationalism were also linked psychologically with 'extreme pro-group attitudes' - agreeing with statements like 'I would fight someone insulting or making fun of America as a whole’ and ‘I would sacrifice my life if it saved another American's life’. When combined with dogmatic personality traits, extremism surfaces.
"The extremist mind - a mixture of conservative and dogmatic psychological signatures - is cognitively cautious, slower at perceptual processing and has a weaker working memory," the researchers said. "This is combined with impulsive personality traits that seek sensation and risky experiences."
Dr Zmigrod said their methods of analysis were 15 times more accurate at picking out who might be an extremist than demographics alone.
"Many people will know those in their communities who have become radicalised or adopted increasingly extreme political views, whether on the left or right. We want to know why particular individuals are more susceptible.
"By examining 'hot' emotional cognition alongside the 'cold' unconscious cognition of basic information processing we can see a psychological signature for those at risk of engaging with an ideology in an extreme way.
"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."
The researchers said there was more to learn - particularly in the differences they found amongst conservatives, with social conservatives scoring high on agreeableness and perceiving risk, but economic conservatives not.