Mistakes Were Made (But Not by Me): Why We Justify Foolish Beliefs, Bad Decisions, and Hurtful Acts

by Carol Tavris

Neuroscientists have shown that these biases in thinking are built into the way brains process information—all brains, regardless of their owners’ political affiliations. In one study, people were monitored by magnetic resonance imaging (MRI) as they tried to process either dissonant or consonant information about George Bush or John Kerry. Drew Westen and his colleagues found that the reasoning areas of the brain virtually shut down when participants were confronted with dissonant information, and the emotion circuits of the brain were activated when consonance was restored.14 These mechanisms provide a neurological basis for the observation that once our minds are made up, it can be a major effort to change them. Indeed, even reading information that goes against your point of view can make you all the more convinced you are right. In one experiment, researchers selected people who either favored or opposed capital punishment and asked them to read two scholarly, well-documented articles on the emotionally charged issue of whether the death penalty deters violent crimes. One article concluded that it did, the other that it didn’t. If the readers were processing information rationally, they would realize that the issue was more complex than they had previously thought and would therefore move a bit closer to each other in their beliefs about capital punishment as a deterrent. But dissonance theory predicts that the readers would find a way to distort the two articles. The...