The end is near

There's a sign on Route 82 at the Route 1 bypass predicting that May 21, 2011, is going to be Judgment Day. A religious group has pinpointed this day for "The Rapture" and believes that God will destroy this world 5 months later, on Oct. 21. "These dates are 100% accurate and beyond dispute," says its website.
Clearly somebody was motivated enough to have these signs printed up and to go out and post them. How is he or she going to feel, I wondered, if May 21 passes by without incident and the sun comes up just as usual on Oct. 22?
"When Prophecy Fails," a classic 1956 book by social psychologists Leon Festinger, Henry Riecken, and Stanley Schachter, addressed this very issue. They studied a UFO cult that believed the world was going to end in a flood on Dec. 21, 1954, but because they were such fervent believers they alone were going to be rescued on a flying saucer. The book gives an account of the key evening:

• Dec. 20: The group expects a visitor from outer space to call upon them at midnight and to escort them to a waiting spacecraft. As instructed, the group goes to great lengths to remove all metallic items from their persons. As midnight approaches, zippers, bra straps, and other objects are discarded. The group waits.
• 12:05 A.M., December 21. No visitor. Someone in the group notices that another clock in the room shows 11:55. The group agrees that it is not yet midnight.
• 12:10 A.M. The second clock strikes midnight. Still no visitor. The group sits in stunned silence. The cataclysm itself is no more than seven hours away.
• 4:00 A.M. The group has been sitting in stunned silence. A few attempts at finding explanations have failed.
• 4:45 A.M. Another message by automatic writing: "The cataclysm has been called off."

To try to reconcile their cognitive dissonance between what had happened and what they had believed, the members decided that aliens actually were visiting them, only in human form. They also believed that by believing so strongly and preparing so diligently for the planet's doom, "they had spread so much light that God had saved the world from destruction."