The term dissonance refers to a lack of harmony in things. It is a state of disequilibrium where two are more things are in disagreement with one another.

The theory of cognitive dissonance was put forward by an American psychologist, Leon Festinger in 1957.

Cognitive dissonance refers to the state of mind, in which, the individual holds two conflicting beliefs or attitudes. Since the individual holds two opposing beliefs, he acts according to one belief which is basically in opposition to the other belief he holds. This inconsistency in action and beliefs results in a state of tension or dissonance.

For instance, a smoker knows that smoking causes serious health complications. However, he still smokes due to his addiction to it. He smokes but he also knows that he is doing something that he is not supposed to do. In such a case, the smoker is in a state of cognitive dissonance. He smokes but at the same time, also repents over smoking at some corner of his mind.

Cognitive dissonance results in a state of confusion, stress, or tension. In most cases, the individual may change his cognition in an attempt to reduce the stress caused by cognitive dissonance. For instance, a student, who studies till late at night, knows that a good amount of sleep is essential for brain health and general health. However, he keeps waking all night to study his books and justifies it by saying to himself that it is okay because the study is also a productive and beneficial activity for him. In the smoker’s example, the person usually justifies his smoking habit by saying to himself (by deceiving his own self) that it is okay for him to smoke now because he will be able to quit it soon one day.

Following are some of the conditions where dissonance can occur.

When someone has two make a choice in available alternatives and does not know which one is the best. Decision made in such conditions is sometimes followed by cognitive dissonance. For instance, we go to a store to buy a shirt. We like two shirts in the store and have to decide which one to buy. We think about the pros and cons of both shirts such as price, the occasion for which it will be used, how it will look and so on. Then, we make a decision to choose one shirt. After we buy the shirt and come home, we usually start thinking whether this shirt (that has been bought) is good, or we should have bought the other one. It results in a state of cognitive dissonance for us. In such a situation, some people may even go back to the store and change the shirt for the other one.

This is because the situation to decide among many choices is quite complex. We make a choice depending on our evaluation, but it looks inconsistent to our beliefs later on. All the positive attributes of the rejected choice come to our mind and the negative attributes of the selected choice start to appear to us. It produces a state of psychological discomfort. However, we do try to reduce our stress and restore the consistency of our minds by giving reasons to ourselves to justify that we have made a good choice.

Cognitive dissonance also occurs when a person acts against his beliefs. This generally happens when a person behaves against the ethics and norms which he thinks that he should always uphold.

For instance, a person believes that it is wise to control anger emotions and to be soft-spoken towards others in a debate. However, when the same person engages in some arguments with another person, he may become angry and behave very aggressively. During this situation as well as after the situation ends, the person undergoes a state of cognitive dissonance because he feels that his action are/were inconsistent with his beliefs. He repents and thinks that he should have not behaved aggressively.

As noted earlier, people try to reduce their stress by changing their cognition. For instance, the person in the above situation may justify his aggressive behaviour by saying to himself that actually, the other person was quite rude, and this made him behave aggressively.

Insufficient justification is a state where an individual fails to find justification for his counter-attitudinal behaviour. In such a case, there is no or less external justification to the counter-attitudinal behaviour which pushes the individual into cognitive dissonance. For instance, a person may behave against his personal belief or attitude due to his job demands. He does so to fulfil the demand of his job but at the same time, he feels that he is doing something in contrast to what he thinks he should do. In such cases, if the person finds some justification for his counter-attitudinal behaviour, he may not undergo cognitive dissonance. However, in some cases, there may be no or less external justification for his counter-attitudinal behaviour which leads to cognitive dissonance.

Since there is no external justification, the individual may reduce his stress by giving himself an internal justification. For instance, he may think about the reward of his behaviour. This is why some people may engage in counter-attitudinal behaviour simply because of the rewards they will receive in return. The greater the reward, the lesser would be the cognitive dissonance.

The fear of threats and punishment may also compel an individual to act against his beliefs or attitudes. The fear of threats and punishment may bring a change in the behaviour of the person but the belief and attitude of a person remain unchanged. This means that the individual may engage in some activity due to fear of threats and punishment, but he would still condemn his actions in his mind because beliefs and attitudes define the act as inappropriate. Therefore, this conflict between the actions and beliefs results in cognitive dissonance. Like any other instance of cognitive dissonance, the individual may try to reduce the stress caused by cognitive dissonance by providing himself with the justification that he was compelled to act that way.