Cognitive dissonance: when thinking and acting do not match

In short: Cognitive dissonance is the uncomfortable feeling that arises when beliefs, knowledge and behaviour contradict each other. The social psychologist Leon Festinger described the phenomenon in 1957.

In more detail: People strive for inner consistency. When something does not fit, we try to resolve the contradiction, often not by changing our behaviour but by adjusting our thoughts or playing the contradiction down.

In detail

• Typical example: Someone who smokes and knows that smoking is harmful experiences dissonance and may tell themselves: “My grandad smoked too and lived to 90.”
• Three ways out: Change the behaviour, change the belief, or add new, reassuring thoughts.
• Justification after decisions: After an expensive purchase, many people stress the advantages and ignore the drawbacks so that the choice feels right.
• Justifying effort: Things that took a lot of effort are often rated especially positively, such as a demanding training course or a tough entrance exam.
• Classic experiment: In Festinger and Carlsmith (1959), participants rated a boring task more positively if they had been paid only a little money to lie about it, because the small reward did not justify the lie.
• Link to thinking errors: Dissonance strengthens confirmation bias, because contradicting information feels unpleasant (kognitive-verzerrungen).
• Spotting it in everyday life: Excuses, dismissing criticism and a strong urge to defend yourself can be signs of dissonance.
• Using it constructively: If you notice the discomfort, you can take it as a prompt to change your behaviour deliberately instead of just looking for reasons (gewohnheiten-aendern-und-aufbauen, entscheidungen-treffen-psychologie).