Psychological projection is the process of misinterpreting what is "inside" as coming from "outside". It forms the basis of empathy by the projection of personal experiences to understand someone else's subjective world. It is a defense mechanism in which the ego defends itself against disowned and highly negative parts of the self by denying their existence in themselves and attributing them to others, breeding misunderstanding and causing untold interpersonal damage. For example, someone who is rude may constantly accuse others of being rude.