'Cognitive Dissonance' is now a recognised term for describing a particular state of mind; a state which seeks to deny an inconvenient truth. The 'truth' in question, in Festinger's study in 1950s America, was the failure of Jesus to return to earth on a flying saucer.
A group of flying saucer enthusiasts had convinced themselves, due to the broadcast 'insights' of one of their number, that the world was about to end. Hope for salvation lay in awaiting Christ's imminent return to rescue a faithful few and take them to a distant star.
The daily meetings of this deluded group were infiltrated by some research students. This book records the students' every observation. The refusal to acknowledge the disappointment at Jesus' non arrival, and the world's continued existence after the prophesied date, gave rise to the term 'cognitive dissonance'.
Festinger remarks on parallels with the Millerites of the 1840s, another, much larger, group, whose End of the World prophecies were confounded. Rather than acknowledge they were wrong, they regrouped as the Seventh Day Adventists who meet to this day. A respectable case is made for the survival of Christianity beyond the disappointment of the Crucifixion. So much had been invested in the hopes for Jesus' salvific mission that adjusting to a a new reality proved, and for many still proves, impossible.
A global movement has lasted for two millennia on account of man's refusal to harmonise reality (Christ was crucified and has not been seen since, save in a mythical resurrection and ascension)with cognition (Christ is alive and will return to Earth).
Festinger's experiment can be seen to reflect that delusion, not on a global scale, but within the confines of a suburban house and