Who Won the U.S. Presidential Debate?

Conservative voters have slightly larger amygdalas than progressive voters—by about the size of a sesame seed. In a replication study published September 19 in the journal iScience, researchers revisited the idea that progressive and conservative voters have identifiable differences in brain morphology, but with a 10x larger and more diverse sample size than the original study.

Their results confirmed that the size of a person's amygdala is associated with their political views but failed to find a consistent association between politics and the anterior cingulate cortex (ACC).

Anatomical differences in both the amygdala and ACC varied depending on a person's economic and social ideology—which aren't necessarily aligned—indicating that relationships between political ideology and brain structure are nuanced and multidimensional.

"It was really a surprise that we replicated the amygdala finding," says first author and political psychology and neuroscience researcher Diamantis Petropoulos Petalas of The American College of Greece and member of the @HotPoliticsLab at the University of Amsterdam. "Quite honestly, we did not expect to replicate any of these findings."

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