Cognitive dissonance is a psychological phenomenon that occurs when a person holds two or more conflicting beliefs, attitudes, or values, or when their behavior does not align with their beliefs or values. This creates a feeling of mental discomfort, which can lead to an alteration in one of the attitudes, beliefs, or behaviors to reduce the discomfort and restore balance. Some examples of cognitive dissonance include smoking even though one knows it is harmful to their health, or eating meat while considering oneself an animal lover. Cognitive dissonance can be experienced as psychological stress when a person participates in an action that goes against one or more of their beliefs or values. According to cognitive dissonance theory, when two actions or ideas are not psychologically consistent with each other, people do all in their power to change them until they become consistent. Cognitive dissonance theory proposes that people seek psychological consistency between their expectations of life and the existential reality of the world, and to function by that expectation of existential consistency, people continually reduce their cognitive dissonance in order to align their cognitions (perceptions of the world) with their actions. Cognitive dissonance can lead to anxiety, regret, low self-worth, shame, stress, reduced self-esteem, and anger. However, confronting cognitive dissonance can often lead to positive results, such as shifting problematic beliefs or harmful habits.