Cognitive Dissonance Theory (Festinger)

1The world did not end

In 1954 a small group in the United States, led by a woman who said she received messages from beings on another planet, believed that a great flood would destroy much of the world on 21 December, and that a flying saucer would rescue the faithful. Some members gave up their jobs, homes and savings. The psychologist Leon Festinger and two colleagues joined the group, pretending to be believers, to watch what would happen when the prophecy failed.

No flood came and no saucer arrived. Common sense predicts that the believers would give up their belief. Instead, several of them announced that their faith had saved the world, and began, for the first time, to seek publicity and recruit new members (Festinger, Riecken and Schachter, 1956, When Prophecy Fails). Why would people believe more strongly after the evidence went against them?

21. The theory

Festinger (1957) proposed that inconsistency between cognitions creates dissonance, an uncomfortable state that people are motivated to reduce, much as hunger motivates eating. The greater the importance of the cognitions and the more of them that clash, the greater the dissonance. Figure 1 shows the ways people reduce it.

Only the first route changes the behaviour. The other three change the mind to fit the behaviour, which is why dissonance theory is often summed up as "we rationalise what we have done".

32. The classic evidence

Induced compliance: Festinger and Carlsmith (1959)

Seventy-one male students at Stanford University spent an hour on deliberately boring tasks, such as turning pegs a quarter-turn at a time. Some were then paid US$1, and others US$20, to tell the next participant (a confederate) that the tasks had been enjoyable. A control group told no lie. Afterwards all rated how enjoyable the tasks had really been, on a scale from −5 to +5.

Those paid US$20, a large sum in 1959, had a sufficient reason for lying. Those paid US$1 had insufficient justification, so they reduced their dissonance by deciding the tasks had not been so bad after all.

Effort justification: Aronson and Mills (1959)

Women students who had to pass an embarrassing "initiation" to join a discussion group later rated a deliberately dull group discussion as more interesting than women who had a mild initiation or none. The more we suffer for something, the more we value it. This may help explain why harsh initiation rituals for new pupils or recruits persist, and why they should be stopped: they bind people to groups through suffering, not through the group's real worth.

Post-decision dissonance: Brehm (1956)

After choosing between two similarly attractive products, people rated the chosen one more highly and the rejected one lower: the "spreading of alternatives". Keith Chen and Jane Risen (2010) later showed that the standard design of this study can produce the same pattern through a statistical artefact even with no dissonance, so its evidence is weaker than it looked.

43. Does it replicate?

In 2024 David Vaidis and colleagues ran a pre-registered replication of the induced-compliance effect in 39 laboratories in 19 countries, with 4,898 participants. Students wrote an essay supporting a position they disagreed with, under either "high choice" or "low choice". Writing the essay did shift attitudes towards the essay's position, but the key prediction of dissonance theory, that the shift would be larger under high choice, was not found. Defenders of the theory argue that the procedure differed from the classic studies; the authors reply that much of the older evidence came from small studies. The idea that people justify their actions remains widely accepted, but some of its classic demonstrations are now in doubt.

54. Using dissonance for good

In hypocrisy induction, people first argue publicly for a healthy or responsible behaviour and are then reminded of times they failed to practise it. The gap between word and deed motivates change. Elliot Aronson's team used this to reduce water use in showers (Dickerson and colleagues, 1992) and to increase safer-sex intentions and condom purchases among students (Stone and colleagues, 1994).