Leon Festinger, a social psychologist at Stanford University, was studying how and why rumors spread when he read about the aftermath of a severe earthquake that shook India in 1934. People who lived in a region of the country that had felt the shock but were spared death and destruction began circulating rumors that other terrible disasters were about to befall them -- a cyclone, a flood, another earthquake or "unforeseeable calamities."
Why, Mr. Festinger wondered, would rumors arise that provoked rather than allayed anxiety, especially among people who hadn't suffered any immediate loss? And why were the rumors so widely accepted?
His conclusion derailed his analysis of rumors and put him on the track of a milestone in psychological theory: When feelings and facts are in opposition, people will find -- or invent -- a way to reconcile them. The people who had narrowly escaped the earthquake were scared, but their fear seemed largely unjustified. The rumors provided people with information that fit how they already felt, reducing what Mr. Festinger called their "cognitive dissonance." His 1957 book on the subject was widely influential in many fields, and the theory is still studied and applied in advertising and market research, politics, education and health.
Why, for example, do people who know cigarettes are bad for their health continue to smoke? This is classic cognitive dissonance: They know one thing and feel another.
Mr. Festinger believed this incongruity is as uncomfortable to the human organism as hunger. One way or another, the anxiety must be assuaged. So the smoker builds a bridge -- a rationalization -- from feeling to fact: If he stopped smoking, he'd gain weight, which would also be unhealthy; some risks are worth taking to have a full life; the risks of smoking have been exaggerated. Indeed, in a 1954 survey asking people if they felt the link between lung cancer and cigarettes had been proven, 86 percent of heavy smokers thought it wasn't proven, while only 55 percent of nonsmokers doubted the connection.
Cognitive dissonance also explains why many people read advertisements for products they have already bought. Almost inevitably, they have made a choice that involved compromises. The car they purchased gets great mileage, but isn't stylish or powerful. After reading a loving description in a newspaper or magazine, they feel less conflicted about their decision -- their dissonance has been reduced.
Because of cognitive dissonance, facts can be as malleable as clay. In 1951, the Princeton and Dartmouth football teams played a particularly competitive and rough game. A sample of students from each school were later shown the same film of the game and asked to note incidents of rough or illegal play. Dartmouth students saw mostly Princeton's offenses; Princeton students saw mostly Dartmouth's.
But where Mr. Festinger found the richest raw material for his theory was in a cult that developed in Chicago in 1954. A woman Mr. Festinger called Marion Keech claimed she was receiving messages from another planet, Clarion. The messages predicted that on a given date, a cataclysmic flood would engulf most of the continent. Those who joined Mrs. Keech's sect would be picked up by flying saucers and evacuated from the planet.
A brief newspaper story about the cult came to the attention of Mr. Festinger. He was reminded of the followers of a New England farmer, William Miller, who predicted that the Second Advent of Christ would occur in 1843. Thousands of people who believed Miller's prophecy prepared for the world to end. But 1843 passed without incident. Far from admitting that the prediction was wrong, the Millerites attempted to lessen their cognitive dissonance in two ways: They changed the date of the Second Advent to the following year and stepped up their campaign, trying to convince even more people that their belief was right.
Mr. Festinger and two colleagues infiltrated Mrs. Keech's movement, acting as participants for three months. They watched as about two dozen well-educated, upper-middle-class people, "who led normal lives and filled responsible roles in society," quit their jobs and threw away their possessions. Before the dates of the expected flood, the cult was mostly averse to publicity and had no interest in attracting other believers.
On the day before the flood, the group was told that at midnight a man would appear at Mrs. Keech's house and take them to a flying saucer. But no knock came at her door, and the group struggled to find an explanation for why there would be no flying saucer or flood. At 4:45 a.m., the group said, a message arrived from God saying He had stayed the flood because of their strength.
What interested Mr. Festinger was not so much this face-saving explanation as what the cult members did in the following weeks. Rather than shunning public attention as they had before, they began zealously proselytizing. "There were almost no lengths to which these people would not go now to get publicity and to attract potential believers," Mr. Festinger wrote. "If more converts could be found, then the dissonance between their belief and the knowledge that the prediction hadn't been correct could be reduced."