Confirmation biases provide one plausible explanation for the persistence of beliefs when the initial evidence for them is removed or when they have been sharply contradicted. This belief perseverance effect has been first demonstrated experimentally by Festinger, Riecken, and Schachter. These psychologists spent time with a cult whose members were convinced that the world would end on December 21, 1954. After the prediction failed, most believers still clung to their faith. Their book describing this research is aptly named "When Prophecy Fails".