Cognitive Dissonance
The mental discomfort experienced by a person who simultaneously holds two or more contradictory beliefs, ideas, or values, such as by a situation in which a belief of a person clashes with new evidence perceived by that person.
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Origin
Leon Festinger introduced the term in his 1957 book A Theory of Cognitive Dissonance, published by Stanford University Press. The theory grew directly from his 1956 fieldwork with co-authors Henry Riecken and Stanley Schachter, documented in When Prophecy Fails — a study of a doomsday cult whose members, after their predicted apocalypse did not arrive, became more fervent believers rather than abandoning their faith.
Updated February 22, 2026