Cognitive dissonance is defined as the state of having inconsistent thoughts, beliefs, or attitudes in relation to behavioral decisions. Coined by Leon Festinger (1957), actions or new information that contradict personal beliefs, ideals, and values (e.g., a woman believes it is important to take care of the environment, but drives a car that is not environmentally-friendly) causes psychological stress from the internal inconsistency; this psychological stress is “cognitive dissonance.” Cognitive dissonance can be resolved through behavior or attitude changes (e.g., justifying the conflicting behavior by adopting a new belief system or avoiding contradictory behaviors).
Festinger, L. (1957). A theory of cognitive dissonance. Stanford, CA: Stanford University Press.