In December 1954, a doomsday cult was awaiting the arrival of a UFO which would rescue the faithful. Leon Festinger, a social psychologist, had infiltrated the cult to see how they would respond when the UFO failed to appear and the world didn’t end. Remarkably, the cult emerged from their failed prediction with renewed strength, convinced that they had “spread so much light that God had saved the world from destruction.”. Cognitive dissonance is a phrase coined by Festinger in 1956 to explain this sort of response. It refers to the discomfort we feel when trying to simultaneously hold two contradictory ideas in our mind; we reflexively try to resolve this discomfort, often pre-consciously. It’s a striking and elegant idea which can explain aspects of a wide range of seemingly strange human behaviours, from doomsday cults and initiation ceremonies to post-purchase rationalizations.