The cognitive dissonance theory was created by Leon Festinger and he defined it as “distressing mental state caused by inconsistency between a persons two beliefs or a belief and an action”. The book also stated that there were three was that people can prevent dissonance. The three ways were Selective exposure, post decision dissonance and minimal justification. Selective exposure was when people avoid new information because it might interference with their own beliefs. Then post decision dissonance was when rethinking a decision that you already made and minimal justification was a way to stimulate an attitude change in others is to offer just enough incentive to elicit counterattitudinal behavior.