How the theory works
Someone who knows smoking is dangerous but continues to smoke has two thoughts in tension. They can quit, change their beliefs about the risk, or add new thoughts that soften the conflict. Festinger argued that the discomfort is motivating, and that people will often change an attitude to bring it into line with what they have done.
The classic experiment
In a 1959 study, participants paid a small sum to tell someone a dull task was enjoyable later rated it as more enjoyable than those paid a large sum. A small payment gave too little justification for the lie, so participants seemingly changed their attitudes instead. Later work also studied choices between alternatives and effort justification.
Debate
Rival explanations include self-perception, in which people simply infer attitudes from behaviour. Recent multi-lab replication work has questioned how robust the classic choice manipulation is. The general phenomenon is widely accepted, but the conditions under which it emerges and its mechanism are still being worked out.
Further reading
- Festinger, L. (1957). A theory of cognitive dissonance. Stanford University Press.
- Festinger, L., & Carlsmith, J. M. (1959). Cognitive consequences of forced compliance. Journal of Abnormal and Social Psychology, 58, 203-210.