Cognitive dissonance theory, developed by Leon Festinger in 1957, explains the mental discomfort that arises when a person holds two conflicting beliefs or values. This discomfort often leads individuals to change their attitudes or behaviors to restore harmony. For example, if someone values health but smokes cigarettes, they may downplay the risks of smoking to reduce the dissonance. The theory suggests that people are motivated to seek consistency in their thoughts and actions. When faced with dissonance, they might rationalize their behavior, change their beliefs, or even avoid information that contradicts their existing views, thereby maintaining psychological comfort.