In the field of psychology, cognitive dissonance occurs when a person holds two or more contradictory beliefs, ideas, or values, or participates in an action that goes against one of these three, and experiences psychological stress because of that. When two actions or ideas are not psychologically consistent with each other, people will do all in their power to change them until they become consistent.[1] The discomfort is triggered by the person’s belief clashing with new evidence (facts) perceived, wherein they will try to find a way to resolve the contradiction to reduce their discomfort.[2][1]
from Wikipedia