Liberal vs. Conservative: A Neuroscientific Analysis with Gail Saltz

source: Big Think     2016年5月29日
What the difference in brain structure between liberals and conservatives? And where do our political convictions come from: rational deliberation, or biological determinism? Psychiatrist Gail Saltz explains. Read more at BigThink.com: http://bigthink.com/videos/gail-saltz...

Transcript - So I think what’s really fascinating is that there have been a number of recent studies looking at brain structural differences between liberals and conservatives. And what’s been found in several studies is that liberals tend to have a larger anterior cingulate gyrus. That is an area that is responsible for taking in new information and that impact of the new information on decision making or choices. Conservatives tended on the whole to have a larger right amygdala. Amygdala being a deeper brain structure that processes more emotional information - specifically fear based information. So it’s really responsible for the flight or fright response. And this isn’t everybody. It’s not black and white and of course then, you know, what about all of the people in the middle? But basically the study showed that if you just based it on brain structural size different you could predict who would be a conservative and who would be a liberal with frequency of 71.6 percent.

71.6 percent is a pretty high ability to predict who is a conservative and who is a liberal just from brain structure. When you look at what your parents were in terms of predicting what you might be in terms of conservative versus liberal, that enabled you to predict in studies at a rate of 69.5 percent. So very close. Not quite as good and why is that interesting? It’s because the brain is plastic. So the question as to whether you have a brain structure to start with that informs whether you will be a liberal or conservative or whether the formation of certain thoughts from your parents for example shapes your brain structure. Because the brain is plastic and ever changing, particularly in youth. So does thinking certain thoughts or predominantly let’s say utilizing your right amygdala versus your anterior cingulate gyrus inform the growth of those areas and therefore help you predict later who is liberal and who is conservative.

So in terms of interpreting the meaning of different sized structures for a liberal versus a conservative I think you have to look at what that area is predominantly responsible for. So for instance for conservatives if you’re right amygdala is enlarged and that’s the fear processing area you would expect maybe choices or decisions or character and personality to be more informed by a response to a fearful situation. So for example conservatives in fact in personality studies do tend to rate higher in areas of stability, loyalty, not liking change, being more religiously involved in terms of decision making, having that rate higher for them in making certain choices. And if you look at liberals from a personality character standpoint you’re going to find stronger ratings in terms of liking change wanting to actually base decision making on new information, on science information. And so those differences are not surprising in light of these brain structural differences.

Being a liberal or being a conservative really is not black and white. It’s really a bell shaped curve where, you know, someone who considers themselves conservative may be far less conservative so to speak than someone else who still calls themselves a conservative. And that bell shaped curve continues all the way through where in the middle there may be a large group that calls themselves independents.