Peering inside the brain with MRI scans, researchers at University College London found that self-described conservative students had a larger amygdala than liberals.

The amygdala is an almond-shaped structure deep in the brain that is active during states of and . Liberals had more gray matter at least in the anterior cingulate cortex, a region of the brain that helps people cope with complexity.

The results are not that surprising, as they fit in with conclusions from other studies. Just a year ago, researchers from Harvard and UCLA San Diego reported finding a "liberal" . This gene had a tiny effect, however, and worked only for adolescents having many friends. The results also mesh with psychological studies on conflict monitoring.

What It Means

There is a big unknown underlying these findings. Supposing that the size of one's amygdala really does increase the likelihood of being a conservative, is the size of the amygdala determined at birth, or does it perhaps increase with frightening experiences, such as authoritarian and corporal ?

Similarly, one might ask whether the gray matter difference is affected by exposure to educational challenge, social diversity, or childhood cognitive enrichment.

The "born" versus "acquired" perspective on political attitudes is important to psychologists. After all, if political proclivities are fixed at birth in terms of brain anatomy, there is little hope of change. Most of us would probably like to see a world in which political attitudes were less polarized and more changeable, but that may be a pipe dream.

Meanwhile, the neuro-scientific fact of two very different political creatures helps clarify much of the political antics of modern democracies.

Most societies are divided into a party that wants change (the more liberal party) and one that is afraid of change (the conservatives). The liberal party is generally more intellectual and the conservative party is more anti-intellectual.

The conservative party is big on national defense and magnifies our perception of threat, whether of foreign aggressors, immigrants, terrorists, or invading ideologies like Communism. To a conservative, the world really is a frightening place.

Given that their brains are so different, it is hardly surprising that liberals and conservatives should spend so much time talking across each other and never achieving real dialogue or consensus.

As scientists, we hope that these results are replicated because they shed so much light on political behavior. As citizens, we would prefer if politicians were not divided into such different categories of a political animal.

If everyone was born with the same brain potential to acquire either conservative or liberal views, then we could be more about prospects for political communication and consensus-building. If voters were of like brain, perhaps they could be of like mind.