ABC News ran this story about a recent meta-analysis of brain research (from ProCon.org) on Republicans and Democrats - the emerging understanding is that there are some general differences in the brains of people who tend to be more conservative vs those who tend to be more liberal.

Overviews for each scientific study, and in many cases the studies themselves, are available on the ProCon.org website. Here are a few of the findings:

The studies – including ones published in Science, Nature, and Current Biology – were done between 2007 and 2012. Some of the differences they found between liberals and conservatives included:

* Liberals are more open-minded and creative whereas conservatives are more orderly and better organized.

* Liberals have more tolerance to uncertainty (bigger anterior cingulate cortex), and conservatives have more sensitivity to fear (bigger right amygdala).

* Compared to liberals, conservatives are less open to new experiences and learn better from negative stimuli than positive stimuli.

It's always problematic to generalize about large groups, but the accumulating evidence seems to be growing. According to psychiatrist Greg Appelbaum, the studies suggests that conservatives tend to try to avoid self-harm, while liberals try to avoid collective group harm. But that is an assessment of behavior - most of these studies look at brain structure and function.

The inevitable question is which comes first, beliefs or brain structure? Conservatives tend to have a larger right amygdala, associated with fear response - we know that the amygdala grows as a response to chronic stress and/or trauma. In this context, a fear-based worldview may be a healthy adaptive response.

Anyway . . . take these types of studies for what they are worth. 

Conservatives and Liberals Have Different Brains, Studies Show

Conservatives and liberals may have one less thing in common: neurology.

ProCon.org has gathered 13 peer-reviewed studies of behavioral and neurological studies and come to the conclusion that differences between Republicans and Democrats are more than skin-deep.

“Basically, the different sides have been yelling at each other for millennia, and we’re trying to figure out what could be the root cause of this,” said Steven Markoff, ProCon.org’s founder.

The studies looked at things like differences between groups’ perception of eye movement, and aversion to threatening noises.  Researchers also noted that Democrats had larger anterior cingulate cortexes, which are associated with tolerance to uncertainty, while Republicans had larger right amygdalas, which are associated with sensitivity to fear.

“Everybody seems to basically agree, and these are people that have scientific backgrounds,” Markoff said of the repetition in the studies. “That to me is probably the biggest eye-opener.”

Although Markoff concluded the studies combine to mean that the different groups communicate in different ways, psychiatrist Greg Appelbaum said the studies point toward conservatives’ tendency to avoid something called self-harm, while liberals avoid collective group harm.

That said, Appelbaum the studies are not representative of all Republicans or Democrats, given that researchers are weaving different small studies together to draw conclusions, and several different opinions designate whether someone is liberal or conservative.

“It’s important to keep in mind that this is a big, multidimensional space,” Appelbaum said.

He also said someone’s brain makeup doesn’t necessarily predispose that person to think one way or another politically, calling it a “chicken or the egg issue.” In fact, it’s possible that a person’s political thinking can change their physiological traits.

It makes sense to consider a person who plays video games and has good reaction times, he said. Does that person play the games because he (or she) is good at them and gets positive reinforcement or does that person hone the abilities by playing video games?

Regardless of the caveats, Markoff said the collection of studies generate an interesting discussion.

“The real reason ProCon is here is to foster critical thinking, and I can’t think of anything more interesting from a critical thinking standpoint,” he said.