Research suggests that liberals and conservatives have different personality traits and “cognitive styles”: while liberals are more intellectually curious and tolerant of ambiguity, conservatives have a greater desire to reach decisions quickly and are more consistent in the way they make those decisions.
A new study, published online today in Nature Neuroscience, suggests that there may be a neural basis for these differences in cognitive style. The study provides evidence that there are differences in the way the brains of liberals and conservatives respond to situations involving difficult decisions.
In the study, which was led by David Amodio of the Social Neuroscience Laboratory at New York University, 43 participants who were first asked to score their political views on a scale of -5 to +5, with -5 being extremely libral and +5 being highly conservative.
They were then asked to perform a simple task in which they were presented with one of two letters on a computer screen. They were required to press one button if they saw the letter “M” and another if they saw a “W”. While this task was performed, the researchers used an electroencephalogram (EEG) to monitor the participants’ brain activity.
This was repeated 500 times, with one of the letters being presented far more frequently – in 80% of the trials – than the other. By pressing the same button repeatedly, the participants established a routine response. But when the less frequent letter was presented, the correct response required a break in that routine.
It was found that those who considered themselves to be conservatives made more response errors when upon presentatin of the infrequent letters than those who considered themselves as liberals (respectively, 47% and 37% of the time).
The EEG data showed that, during the trials in which the infrequent letter was presented, the anterior cingulate cortex (AAC) was twice as active in liberals than in conservatives.
The ACC is one of the brain’s executive control centres, and is hypothesized to be involved in detecting and signalling conflicts in information processing. So liberals showed significantly more conflict-related brain activity when confronted with a situation in which they are required to break an old habit.
This does not mean, however, that differences in ACC activity are directly correlated to political orientation. Although the brain mechanisms underlying conflict monitoring are already in place at a very early age, the environment is also likely to have a major influence political views.
Amodio, D. M., et al. (2007). Neurocognitive correlates of liberalism and conservatism. Nat. Neurosci. doi:10.1038/nn1979. [Abstract]