Extreme political rivals may share more similarities than expected, new research suggests

In a groundbreaking new study published in the prestigious Journal of Personality and Social Psychology, researchers from Brown University have uncovered startling neural commonalities in how politically extreme individuals process information, regardless of whether they align with the far left or far right of the ideological spectrum. This research challenges long-held assumptions that opposing political beliefs are rooted in fundamentally different cognitive mechanisms. Instead, it suggests that the brains of extremists, no matter their ideology, may mirror each other in remarkable ways when consuming political content.

Utilizing state-of-the-art neuroimaging techniques, including functional magnetic resonance imaging (fMRI), alongside physiological measures such as galvanic skin response and eye-tracking technology, the research team examined the neural and bodily responses of 44 adult participants with varying degrees of political extremism and ideological leanings. The participants were exposed to a politically charged video designed to evoke emotional and cognitive engagement. What emerged was a pattern of synchronized brain activity among those holding extreme political views that starkly contrasted with the more diverse neural responses observed in moderates.

This synchronization was particularly evident during segments of the video featuring intense, emotionally charged rhetoric. Both extreme liberals and conservatives displayed overlapping activation within brain regions implicated in emotional processing, conflict monitoring, and perceptual encoding, including the anterior cingulate cortex and the amygdala. These shared neural signatures underscore the compelling influence of ideological fervor rather than the content of the beliefs themselves on cognitive function.

Equally revealing was the measurement of physiological arousal. Individuals with more polarized political stances showed heightened galvanic skin responses, indicating elevated emotional arousal when engaging with the political materials. This increase in bodily arousal appeared to amplify the neural synchronization phenomenon, supporting the hypothesis that emotional intensity and visceral engagement play a crucial role in binding individuals to their political ideologies at the neural level.

Dr. Oriel FeldmanHall, co-author and cognitive scientist at Brown University, emphasizes the importance of these findings: “Our data reveal that it’s not merely the specific political views a person holds that shape their brain’s response, but the extremity and emotional investment in those views. This shared neural processing mechanism among extremists may explain why compromise and mutual understanding often elude political dialogue.”

The study also provides empirical backing for the so-called “horseshoe theory” of political ideology, a concept suggesting that political extremes, although diametrically opposed ideologically, share more similarities with each other than with those holding moderate opinions. This neural convergence between opposing fringes shines a light on the psychological and biological underpinnings of political polarization, potentially reframing how society understands ideological divides.

What makes this research particularly compelling is not just the overlap of neural activity, but the associated psychosocial implications. The researchers suggest that recognizing the profound cognitive and emotional commonalities between political extremes could foster empathy and reduce the dehumanization that often exacerbates political conflicts. By viewing political “opponents” through the lens of shared psychological and physiological processes, the possibility arises for more effective communication and reconciliation.

However, the authors caution that their findings are grounded in American political content and self-reported political ideology, which may limit the generalizability of the conclusions across different cultural or political contexts. Political extremism in other nations, or extremism tied to non-political ideologies, may engage distinct neural pathways, prompting the need for future cross-cultural and interdisciplinary studies.

The methodology of the study is particularly noteworthy. The integration of fMRI with skin conductance and eye-tracking allowed a multifaceted exploration of how individuals attend to, emotionally react, and cognitively process political stimuli. This combination elucidates the dynamic interplay of perception, affect, and cognition underlying political belief systems, moving beyond traditional survey or behavioral research methods.

Importantly, the results challenge simplistic dichotomies that paint political opponents as fundamentally “other.” Instead, the neural and physiological data reveal a shared architecture of political cognition among extremists, propelled by emotional arousal. Such findings invite reconsideration of how media, educators, and policymakers approach deeply divisive political conversations.

Co-author Daantje de Bruin notes, “Understanding that strong emotional reactions and tightly held beliefs shape a common reality for extremists—beyond left or right—highlights the psychological mechanisms in play. This insight opens new avenues for interventions aimed at reducing polarization and promoting dialogue.”

This pioneering research aligns with a growing body of cognitive neuroscience exploring the neurobiological roots of social cognition and ideological behavior. Its implications stretch beyond academia, suggesting that emotional regulation and cognitive flexibility might serve as key targets for bridging the widening chasms in political discourse worldwide.

In conclusion, the Brown University study enriches our understanding of political extremism by revealing that the brains of extreme liberals and conservatives alike process political information in convergent ways. Emotional intensity, physiological arousal, and neural synchronization emerge as cornerstones in how polarized individuals engage with politically charged content, challenging existing social narratives and opening the door to novel strategies for enhancing political understanding and empathy.

News Publication Date: 28-Aug-2025

Web References:
https://www.apa.org/pubs/journals/releases/psp-pspa0000460.pdf
http://dx.doi.org/10.1037/pspa0000460

References:
de Bruin, D., & FeldmanHall, O. (2025). Politically extreme individuals exhibit similar neural processing despite ideological differences. Journal of Personality and Social Psychology. Advance online publication. https://doi.org/10.1037/pspa0000460