Ever wonder why Democrats and Republicans can never agree? The answer may lie in the brain.
Liberals and conservatives think in fundamentally different ways, researchers reported in a study published Sunday in the journal Nature Neuroscience.
The study, conducted at New York University, suggested that while conservatives are known to be more structured and persistent when making decisions, liberals are more open to new experiences. Researchers have traced these stereotypes to differences in brain activity.
"Political orientation is based on the fundamental way our brains process information," said lead study author David Amodio, assistant professor of psychology at NYU.
"There is a range of ways that people process information. Some people are more comfortable seeing the pros and cons of a situation. Others are more comfortable to see the situation in only one way."
In the study, participants were seated in front of a computer screen while electrodes recorded electrical activity in their brains.
Two different letters were flashed on the screen for only a few milliseconds. If an M appeared, participants had to press a button in front of them. If a W appeared, participants were told to remain still.
"Eighty percent of the time, the letter M appeared," Amodio said. "The stimulus was so frequent that individuals were just sitting there pressing a button. This behavior became habitual."
Because the letter W appeared only sporadically, it was unexpected and surprised the participants. It took a great deal of mental effort to not press the button — allowing researchers to look at how well the subjects dealt with conflicting information and how quickly they could switch their response patterns.
What researchers found was that liberals were better at processing this conflicting information. The liberals were about 10 percent more likely to hold back from an incorrect response than their conservative counterparts.
Conservatives, on the other hand, were more likely to stay the course. They kept pressing the button even when the letter W flashed on the screen.
More importantly, by using an electroencephalogram, or EEG, during the test, researchers found a fundamental difference in brain activity between liberals and conservatives.
Liberals showed much more brain activity in the anterior cingulate, a region of the brain that processes conflicting information. Increased brain activity in this region might explain why liberals were more accurate on the test.
Researchers not affiliated with the study said perhaps the most fascinating part was that the study showed that conservatives and liberals think differently when they are dealing with an abstract laboratory task — one that has nothing to do with politics.
"The fact that this difference between conservatives and liberals emerges in such a task demonstrates that the attitudes of conservatives and liberals are entrenched," said Dr. Marco Iacoboni, director of the Transcranial Magnetic Stimulation Lab at UCLA.
But psychologist and lawyer Bryant Welch disagreed with the idea that attitudes are entrenched based on political affiliation. Welch, who is writing a book on the subject of brain function and politics titled "State of Confusion," said that despite the study's findings, people with either political belief can be swayed based on experience.