Conflicting actions and beliefs can create discomfort
Cognitive dissonance can arise when important beliefs and behaviour conflict. Someone who values punctuality but repeatedly arrives late may feel uncomfortable about the inconsistency. That discomfort can lead to changed behaviour, a revised belief or a justification that makes the conflict feel smaller.
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People can resolve the mismatch in different ways
A person sees themselves as dependable but forgets an important commitment. The event conflicts with an aspect of their self-understanding.
Cognitive dissonance describes an uncomfortable state associated with certain inconsistencies among beliefs, attitudes and actions. Not every minor contradiction creates the same degree of discomfort.
The person might respond by changing future behaviour, acknowledging a limitation or explaining the event as an exception. Some explanations may be accurate; others may mainly protect the preferred self-image.
The theory does not say people consciously calculate every justification. It explains why resolving an uncomfortable inconsistency can shape later attitudes and accounts of what happened, rather than simply producing a neutral review of the evidence.