Cognitive dissonance is a psychological term for dissonance relation, describing the state of having inconsistent knowledge, thoughts, beliefs, or attitudes, two conflicting thoughts at the same time, the perception of incompatibility between two cognitions, a motivating state of tension that tends to generate three kinds of dissonance-reducing behaviour: changing one of the cognitions, decreasing the perceived importance of dissonant cognitions, and/or adding further, justifying cognitions (118).
Cognitive dissonance was originally developed as a theory of attitude change, but it is now considered to be a self theory by most social psychologists.
The dissonance theory generates counter-intuitive predictions relating to the effect of free choices, resisting temptations, and telling lies.
The theory of cognitive dissonance states also that contradicting cognitions serve as a driving force that compels the mind to acquire or invent new thoughts or beliefs, or to modify existing beliefs, so as to reduce the amount of dissonance (conflict) between cognitions.
Cognitive dissonance is strongest when incongruity has been noticed between one's self-concept and one's behaviour, e.g. doing something that makes one ashamed. This can result in self-justification as the individual attempts to deal with the threat (193).
Cognitive dissonance typically leads to a change in attitude, a change in behaviour, a self-affirmation, or a rationalization of the behaviour (193).