How your brain makes you a rabid partisan

How the Brain Helps Partisans Admit No Gray -- by Shankar Vedantam (from Washington Post)

President Bush came to Washington promising to be a uniter, but public opinion polls show that apart from a burst of camaraderie after Sept. 11, 2001, America is more bitterly divided and partisan than ever.

We'll leave the pundits to pontificate on the politics, and instead explore a more interesting phenomenon: People who see the world in black and white rarely seem to take in information that could undermine their positions.

Psychological experiments in recent years have shown that people are not evenhanded when they process information, even though they believe they are. (When people are asked whether they are biased, they say no. But when asked whether they think other people are biased, they say yes.) Partisans who watch presidential debates invariably think their guy won. When talking heads provide opinions after the debate, partisans regularly feel the people with whom they agree are making careful, reasoned arguments, whereas the people they disagree with sound like they have cloth for brains.

Unvaryingly, partisans also believe that partisans on the other side are far more ideologically extreme than they actually are, said Stanford University psychologist Mark Lepper, who has studied how people watch presidential debates.

Although it is satisfying to think that your side is right and the other side consists of morons, the systematic errors that can be documented in partisan perception suggest something deeper than deliberate tunnel vision. (Last Monday, this space was devoted to the curious phenomenon of the "hostile media effect," in which pro-Israeli and pro-Arab partisans shown the same TV clips both came to the conclusion that the news accounts were heavily biased in favor of the other side.) What explains these distortions in perception?

In an experiment that pols may want to note closely, researchers recently plopped 10 Republicans and 10 Democrats into scanners that measure changes in brain-blood oxygenation. Such changes are thought to be linked to increases or decreases in particular areas of brain activity.

Each of the partisans was repeatedly shown images of President Bush and 2004 Democratic challenger John F. Kerry .

When Republicans saw Kerry (or Democrats saw Bush) there was increased activation in brain areas called the dorsolateral prefrontal cortex, which is near the temple, and the anterior cingulate cortex, which is in the middle of the head. Both these regions are involved in regulating emotions. (If you are eating an ice cream cone on a hot day and your ice cream falls on the sidewalk and you get upset, these areas of your brain remind you that it is only an ice cream, that not eating the ice cream can help keep those pounds off, and similar rationalizations.) More straightforwardly, Republicans and Democrats also showed activation in two other brain areas involved in negative emotion, the insula and the temporal pole. It makes perfect sense, of course, why partisans would feel negatively about the candidate they dislike, but what explains the activation of the cognitive regulatory system?

Turns out, rather than turning down their negative feelings as they might do with the fallen ice cream, partisans turn up their negative emotional response when they see a photo of the opposing candidate, said Jonas Kaplan, a psychologist at the University of California at Los Angeles.

In other words, without knowing it themselves, the partisans were jealously guarding against anything that might lower their antagonism. Turning up negative feelings, of course, is a good way to make sure your antagonism stays strong and healthy.

"My feeling is, in the political process, people come to decisions early on and then spend the rest of the time making themselves feel good about their decision," Kaplan said.

Although it seems paradoxical that people would want to make themselves feel poorly, Kaplan said partisans have a strong interest in feeling poorly about the candidate they are not going to vote for as that cements their belief that they are doing the right thing.

"Democrats looking at Bush may have some positive feelings about the fact he is their leader, so the process of convincing yourself this is someone you don't like when you intend not to vote for him makes sense," he said.

The result reflects a larger phenomenon in which people routinely discount information that threatens their preexisting beliefs, said Emory University psychologist Drew Westen, who has conducted brain-scan experiments that show partisans swiftly spot hypocrisy and inconsistencies -- but only in the opposing candidate.

When presented with evidence showing the flaws of their candidate, the same brain regions that Kaplan studied lighted up -- only this time partisans were unconsciously turning down feelings of aversion and unpleasantness.

"The brain was trying to find a solution that would get rid of the distress and absolve the candidate of doing something slimy," Westen said. "They would twirl the emotional kaleidoscope until it gave them a picture that was comfortable."