A Theory of Cognitive Dissonance

Leon Festinger

6 ideas

1. Dissonance magnitude as function of weighted proportion

   Dissonance is the psychological discomfort that arises when one cognition would follow from the obverse of another. Its magnitude is a function of the importance-weighted proportion of dissonant to relevant cognitions, so it can be reduced by removing dissonant elements, adding consonant ones, or lowering their importance. For a pair of elements, the maximum dissonance cannot exceed the resistance to change of the less resistant element, which would change at that point.

2. Post-decision spreading of chosen alternatives

   After a choice, every attractive feature of the rejected option and every drawback of the chosen one becomes dissonant with the act of choosing. People reduce this by inflating the chosen option's value and devaluing the rejected one, and the effect grows as the alternatives become closer in appeal and the decision more important. Preferences are therefore shaped by decisions as much as decisions are shaped by preferences.

3. Minimal inducement produces maximal private change

   When people are induced to act publicly against their private opinion, private attitude change is greatest when the reward or threat was just barely enough to secure compliance. A large reward or severe threat supplies a consonant justification for the behavior, while a small one leaves the dissonance unjustified and pushes the person to bring belief into line with action. Heavy incentives buy behavior; light incentives change minds.

4. Selective exposure as dissonance management

   When dissonance is present, people tend to seek information that adds consonant cognitions and avoid information likely to increase dissonance, alongside the ordinary curiosity and useful information seeking that Festinger also acknowledges. The relationship is curvilinear: when dissonance is very high, a person may seek out discrepant information that could hasten a change of belief.

5. Failed doomsday prophecy intensifies proselytizing

   A group that had given up jobs, possessions and relationships in the belief that a flood would destroy the world on a specific date did not abandon the belief when the date passed uneventfully. Committed members adopted an explanation that their faith had saved the world and began proselytizing energetically for the first time. Because disconfirmation cannot be denied when commitment is irrevocable, recruiting others to agree becomes the remaining way to add consonant cognitions.

6. Social support as dissonance source and remedy

   Discovering that people like oneself disagree creates dissonance, and its magnitude rises with the relevance and attractiveness of the disagreeing group and with the importance of the issue. The dissonance can be reduced by changing one's own opinion, persuading the others, or derogating them as unlike oneself, and the choice depends on which cognition resists change least. Groups that share the same dissonance offer easy mutual support, which lets objectively untenable beliefs persist and spread, as with rumors after disasters that justify widely shared fears.

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