Cognitive dissonance

Cognitive dissonance is the psychological tension that arises when two cognitions — beliefs, attitudes, or knowledge of one's own behavior — contradict each other. A smoker who knows smoking causes cancer holds two clashing cognitions: "I smoke" and "smoking harms me." The theory, developed by Leon Festinger in the 1950s, holds that this discomfort is motivating: people actively work to reduce it.

There are three main routes to reducing dissonance: change the behavior (quit smoking), change the cognition ("the risks are exaggerated"), or add a justifying cognition ("smoking keeps my stress down, and stress is harmful too"). Because changing behavior is often hardest, people frequently resolve dissonance by revising their attitudes instead — meaning behavior can drive attitude change, not just the reverse.

The classic demonstration is Festinger and Carlsmith's experiment, in which participants performed a boring task and were paid either $1 or $20 to tell the next participant it was enjoyable. Those paid only $1 later rated the task as genuinely more enjoyable — with insufficient external justification for the lie, they reduced dissonance by changing their actual attitude. The well-paid group could attribute the lie to the money and felt no need to change their minds.

Cognitive dissonance is a high-yield attitudes concept on the MCAT, which tests it in the psychological, social, and biological foundations of behavior section, and on the AP Psychology exam within social psychology. Know the definition, the reduction strategies, and the insufficient-justification finding from the $1/$20 study.