BORED WHILE WAITING at the bus stop, Kate sticks a cigarette in her mouth just as she notices a billboard across the road. The small print reads, “Warning: Smoking causes lung cancer, heart disease, emphysema and may complicate pregnancy.” Kate stops for a moment. “How many have I had already today?” she asks herself. But then she lights up. “I don’t smoke that much,” she reasons, to quiet her conscience. “And anyway, I exercise and eat pretty well.”

Every day we wrestle with opposing viewpoints that battle it out in our minds—a tension known as cognitive dissonance. Social psychologist Leon Festinger developed the concept in 1957, from the assumption that human beings fundamentally strive for harmony in their thinking. In the face of contradictory paths, our minds attempt to restore internal peace. We strive for the reconciliation of two conflicting thoughts, even if we must resort to a third to attain it, such as, “Gramps smoked a pack a day, and he lived to be 90.”

Since Festinger's time, numerous researchers have shown how we attempt to reduce mental tension. To become truly content, it seems, we should favor smart choices over emotional ones, but even then, we may need to fool ourselves into thinking we have made the right decision.

The Torture of Choice

Imagine you are looking to buy a used car. Two models stand out—a practical little sedan that does not use much gas and a stylish, fuel-guzzling sports car. After a good deal of back-and-forth, you decide on the sports car. But as soon as you have driven it off the lot, you get an ill feeling in your stomach. Shouldn’t you have purchased the more efficient model?

Consumers call this feeling buyer's remorse. Psychologists call the tension that occurs after such decision making the regret effect. But cognitive salvation comes quickly. “Don’t be an idiot,” you tell yourself. “You’d be too cramped driving in that little thing. And the sports car has side air bags. And a CD player.” The good features of the chosen car get bumped up in estimation, whereas the bad features of the rejected one get exaggerated. Internal harmony is restored.

Festinger's legendary field study involved a sect in a small American town. Sect members were firmly convinced that the world would be destroyed by a massive flood on a certain day. They would be saved, however, by extraterrestrials that would swoop down in flying saucers and whisk them off to another planet, where they would start a new life. Needless to say, doomsday passed uneventfully. But instead of giving up their delusion, the sect members quickly embraced the belief that God had spared the world one more time thanks to their steadfastness.

For the sect members, social support among themselves provided a way to cope with internal contradiction. Others do the same. When forced to act against our conviction, we often adjust the conviction after the fact. We adapt our attitude to our actual behavior, restoring internal balance.

Researchers are finding more and more examples of cognitive dissonance. In 2003 and 2004 studies by Michael I. Norton, now at Harvard Business School, and Benot Monin of Stanford University unveiled a vicarious form of the phenomenon. In one exercise, students who were waiting to participate in an experiment overheard a staged conversation in which an investigator convinced a student to present an opinion during discussion time that would contradict what he believed: he was to speak in favor of tuition increases. Students who heard the coercion and later were part of the discussion voiced less skepticism about tuition hikes than they had previously. Apparently, the knowledge of their classmate's presumed internal conflict caused cognitive tension in them as well. The easiest way to restore equilibrium was to agree with their friend's stated position.

The potential for artificially inducing such attitudinal change is limited, nonetheless. Social psychologists Fritz Strack of the University of Wuerzburg in Germany and Bertram Gawronski of the University of Western Ontario found in a 2004 study of social groups that although we may change our conscious attitudes to justify contradictory behavior, our basic unconscious thoughts and feelings are not easily remolded—even clearly impugned social views such as prejudice. Our personal opinions can be strongly influenced by automatic mechanisms, which may trump deliberate, mature reflection.

Deeds over Words

The question at hand, then, is what actually needs to happen for us not merely to adapt our attitudes to our actions but to act in accordance with our convictions? Social psychologist Robert-Vincent Joule of the University of Provence in France discovered one prescription.

Joule conducted an experiment during the 2002–2003 school year with children aged nine and 10 from 700 families. The goal was to turn the children into environmental activists who would then win over their parents to a more ecologically aware way of life. The students listed behaviors that could change at school and at home. Together with their parents, they filled out a long questionnaire on the topic of energy conservation and pasted an environmental sticker on their refrigerator.

Finally, each child wrote an essay with his or her mother or father about what environmentally harmful practices the family would like to overcome, such as letting the television drone on when no one was watching instead of turning it off. The project culminated in a big environmental fair at the school. In most classes, 100 percent of the students and parents took serious steps to reduce their daily energy consumption.

Joule drew two significant conclusions: To achieve long-term behavioral change, we must first reinforce the desired new attitude by seriously grappling with the topic. Then we have to find a way to acknowledge the new position publicly.

If Kate really wants to stop smoking, she should make a list of all the benefits. Then she should explain her intention to quit to as many acquaintances as possible. She will have examined the reasons for ending her habit and will have committed to them in front of other people. As long as she avoids too many tempting situations to smoke, her chance of making the tough choice permanent—and achieving peace of mind with it—will be much greater.