New research provides evidence that extreme partisanship on both the political left and right is related to cognitive inflexibility. Our findings, which appear in the Journal of Experimental Psychology: General, indicate that people’s political identity is influenced by how they process basic information.

In the current divided political climate, we have been taught to rely on the left-right political distinction as an essential thermometer for who is likely to think like us. But political partisanship in fact has two facets: direction (whether our political beliefs and identity lean politically left or right) and extremity (how strongly and dogmatically we hold these beliefs and identities).

Political psychologists who try to understand the psychological origins of our political views tend to focus on partisan direction, and less on extremity. I was interested in investigating what we can find by studying partisan extremity, and whether we can actually uncover surprising psychological similarities across the political spectrum when we do.

A psychological domain that I’ve been particularly fascinated by is cognitive rigidity. According to the neuropsychological literature, an individual who is cognitively rigid tends to perceive objects and stimuli in black-and-white terms, and this makes it difficult for them to switch between modes of thinking or to adapt to changing environments.

We reasoned that individuals with a tendency towards cognitive rigidity in how they perceive and react to the world generally might be more likely to be rigid and dogmatic about their political beliefs and identities as well, regardless of the partisan direction of their ideology.

In the study, we invited 750 U.S. citizens to complete multiple objective neuropsychological tests that allow us to measure their individual levels of cognitive rigidity and flexibility. We found that individuals who are extremely attached to the Democratic Party or to the Republican Party display greater mental rigidity on these cognitive tests relative to those who are only moderately or weakly attached. Regardless of the direction and content of their political beliefs, extreme partisans had a similar cognitive profile.

This suggests that partisan extremity is psychologically significant – the intensity with which we attach ourselves to political doctrines may reflect and shape the way our mind works, even at the basic levels of perception and cognition. Notably, these findings would have remained hidden if we only considered whether participants were politically left- or right-wing.

One of the most fascinating questions that this research illuminates is that of causality: does mental rigidity make it more likely that we identify with the political extreme? Or does active engagement with politically extreme groups make us more cognitively inflexible? The answer is likely to be – as for most complex phenomena – an interaction of both. Scientifically, we would need longitudinal studies that track people over long periods of time to determine cause and effect.

Importantly, the aim of this research is not to draw false equivalences between different, and sometimes opposing, ideologies, but rather to highlight the common psychological factors that shape how people come to hold extreme views and identities. It may also help us develop antidotes to radicalization.

(If readers want access to the research they can get it with the following link: https://docs.wixstatic.com/ugd/a64c5e_d74504da38e04b428f632aaeb64fcd61.pdf)

Dr. Leor Zmigrod is Gates Scholar and Research Fellow at the Department of Psychology at University of Cambridge.

The study, “The partisan mind: Is extreme political partisanship related to cognitive inflexibility?“, was authored by Leor Zmigrod, Peter Jason Rentfrow, and Trevor W. Robbins.