Conservative and progressive voters appear to be linked to notable differences in brain structure, although these differences are less pronounced than previously thought. This finding comes from a study published in the journal Cell Press iScience, conducted by researchers from the American College of Greece and the University of Amsterdam. Led by Diamantis Petropoulos Petalas, the team analyzed brain scans of 928 individuals aged 19 to 26, whose education levels and political affiliations reflected the Dutch population.
The aim of the study was to explore whether and how political ideology might influence brain structures. The researchers found that conservative voters tend to have slightly larger amygdalae compared to their progressive counterparts. This correlation between political preferences and brain size had been suggested before, in a 2011 study, but that research involved a much smaller and less diverse sample. In the current study, no association was found between political ideology and the anterior cingulate cortex (ACC).
Interestingly, anatomical differences in both the amygdala and ACC varied based on a person’s economic and social ideologies, which are not always aligned. This suggests that the relationship between political beliefs and brain structure is complex and multidimensional. “To be honest,” said Petalas, “we didn’t expect to replicate the 2011 findings, which were based on a sample of just 90 university students from the UK. Political ideology is incredibly complex, encompassing attitudes on a wide range of social and economic issues. It can’t, and shouldn’t, be oversimplified as simply right or left.”
