A doomsday cult's failed prophecy made believers more devoted

When a Chicago group predicted the world would end and it didn't, psychologist Leon Festinger had infiltrated them to watch what happened next. Instead of admitting error, members rationalized the failure and proselytized harder than before -- the sharpest documented case of cognitive dissonance resolving itself through belief, not evidence.

— Leon Festinger, Henry Riecken, and Stanley Schachter, When Prophecy Fails — University of Minnesota Press, 1956
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