By Emiliana R. Simon-Thomas





In recent years, researchers have been trying to determine whether our political opinions—pro-life or pro-choice? Republican or Democrat?—are guided by fundamental differences between the minds of conservatives and liberals. A number of studies suggest that conservatives think in more structured and stable ways, while liberals reason more flexibly, changing their beliefs as they take new experiences into account.

In October, a study published in the journal Nature Neuroscience found that these differences in thinking may be traceable to brain differences. New York University neuroscientist David Amodio and his colleagues showed that brain responses to quick, unexpected changes in strategy differed between liberals and conservatives. First, research participants rated their political attitude on an 11-point scale, ranging from “very liberal” to “very conservative.” Then, with sensors attached to their scalp, they played a simple computer game requiring them to press a button as fast as they could when a certain shape flashed on their screen. When a different, infrequently occurring shape appeared, however, they were supposed to not press the button. Most made mistakes and hit their button when they weren’t supposed to. With each mistake, the researchers recorded a signal coming from the anterior cingulate cortex (ACC), a region of the brain that signals the presence of conflicting information or competing drives. It was as if their brains were saying, “Oops—I meant to do one thing, but I did another.”

Results showed that the more liberal the participant, the greater the “Oops” brain signal and the fewer the number of mistakes made. The authors conclude that the liberals’ brains were more sensitive to how accurate their ongoing responses were, and were more likely to adapt to changing demands. Conservatives’ brains, on the other hand, might be better equipped for tasks that require a more fixed response style.

It remains unclear whether this difference in brain activity is the cause or a consequence of liberal vs. conservative thinking. That is, scientists don’t know whether these brain differences are innate or develop through years of thinking in a certain way. So far, researchers have found no relationship between political orientation and a variety of heritable traits, suggesting that liberalism and conservatism may not be genetically determined. But Amodio’s study does indicate that, at the very least, our political orientation is linked to the way our brains process the world.





Emiliana R. Simon-Thomas, Ph.D., is the science director of the Greater Good Science Center.



