In the field of psychology, cognitive dissonance is described as the mental discomfort people feel when their beliefs and actions are inconsistent and contradictory, ultimately encouraging some change to align better and reduce this dissonance. Relevant items of information include peoples' actions, feelings, ideas, beliefs, values, and things in the environment. Cognitive dissonance is typically experienced as psychological stress when persons participate in an action that goes against one or more of those things. According to this theory, when an action or idea is psychologically inconsistent with the other, people do all in their power to change either so that they become consistent. The discomfort is triggered by the person's belief clashing with new information perceived, wherein the individual tries to find a way to resolve the contradiction to reduce their discomfort.

A belief is a subjective attitude that a proposition is true or a state of affairs is the case. A subjective attitude is a mental state of having some stance, take, or opinion about something. In epistemology, philosophers use the term "belief" to refer to attitudes about the world which can be either true or false. To believe something is to take it to be true; for instance, to believe that snow is white is comparable to accepting the truth of the proposition "snow is white". However, holding a belief does not require active introspection. For example, few individuals carefully consider whether or not the sun will rise tomorrow, simply assuming that it will. Moreover, beliefs need not be occurrent, but can instead be dispositional.