When people learn something that doesn’t agree with what they currently know to be true, they may do one of several things. They may change the first idea to fit the newly introduced second idea; they may add another idea to the first two, to bridge the difference; or they may drop either of the two ideas. All of these are reactions to a state called cognitive dissonance, a mental feeling of discomfort or stress that, according to some psychologists, people will do anything to avoid.
A psychologist named Leon Festinger developed the theory of cognitive dissonance in the mid-1950s. He considered a cult that expected aliens to destroy the earth on a particular date and time, and who were deeply invested in this belief. When this event failed to happen, the members of the cult did not abandon their original idea, but adjusted it by maintaining that the aliens had not come because God, seeing how devoted this small group of humans was, gave his divine protection to Earth. The group then became more fervent in their beliefs.
The members of this cult were protecting their cognitive consonance, the integrity of their knowledge, by creating a new idea that allowed both their convictions and the material truth of a world not destroyed by aliens to coexist. Most of the things that people know aren’t so closely related. These ideas can operate together simultaneously in a state of cognitive irrelevance that poses no challenges to the mind at all. To think that boy scouts are well-behaved and that mittens are warm are two ideas that, taken together, create no tension, for instance. But if a rude boy scout should happen along, cognitive dissonance occurs. It will be necessary for the mind to resolve this somehow, either by revising the previously-held high opinion of boy scouts, imagining that this boy scout will not be a boy scout for long, or forgetting that the bad boy scout ever existed.
Cognitive dissonance happens every time some new concept varies from a related older one, and that occurs every day. Cognitive dissonance, in fact, is an essential aspect of learning. Much of the time, the intensity of the cognitive dissonance is not great and the tension is easily resolved. When the conflicting notions touch closely on a person’s opinion of himself or of a matter he considers to be of importance, however, cognitive dissonance is most painful.