Gray matter: liberal brains vs. conservative brains

Scientists have found that political liberalism and conservatism are correlated with brain structure. It might explain certain tolerances of conflict and sensitivities to fear.
Written by Janet Fang, Contributor

Have you been watching C-Span? I can’t stop.

To mark the Friday expiration of a temporary budget resolution (and perhaps an end to the stalemate that threatens to shut the federal government down), here’s a little liberal versus conservative neuroanatomy.

Researchers claim to have found differences in brain structure between people who identify themselves as either politically conservative or liberal.

Ryota Kanai and colleagues from University College London recruited 90 young adults, who had to rate their political philosophy from very liberal to very conservative.

Then the researchers used magnetic resonance imaging (MRI) to look inside their brains.

  • Liberals tended to have a larger anterior cingulate cortex – an area that becomes active in situations involving conflict or uncertainty. Having a higher capacity to tolerate those kinds of things could allow individuals to accept more liberal views, the authors suggest.
  • Conservatives tended to have a larger right amygdala – a region involved in detecting threats and responding to fearful stimuli. People with this brain structure are likely more sensitive to disgust and threatening facial expressions and tend to "respond to threatening situations with more aggression," the study says.

Just looking at brain scans, the researchers say they could predict who was liberal and who was conservative with about 75% accuracy.

However, the findings don't mean political views are hard-wired into the brain. On that, Kanai wanted to be clear. The data don't prove that these neuroanatomical differences actually cause political differences, but he suspects they might play a role.

"Previously, some psychological traits were known to be predictive of an individual's political orientation," Kanai says. "Our study now links such personality traits with specific brain structure."

As ScienceNOW reports:

(To armchair psychologists, this might explain some stereotypical behavior, such as the spike in blood pressure a hard-core conservative might experience when Fox News plays a new recording from Osama bin Laden, or the half-hour it might take an Earth-loving liberal to decide whether to buy the organic apple flown in from Chile or the local apple treated with pesticides.)

Kanai speculates that subtle size differences in those structures might predispose people to particular cognitive styles or personality traits that in turn make them gravitate toward a particular worldview.

So do the differences cause the divergence in political views, or are they the effect of them? Well, it’s still unclear what a bigger amygdala (or a bigger anything in the brain) actually means in terms of behavior, not to mention how most brain regions have multiple functions.

The study was published in Current Biology today. Colin Firth is an author.

Image: CBS/AP

This post was originally published on Smartplanet.com

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