Psychological projection was first conceptualized by Sigmund Freud as a defence mechanism in which a person unconsciously rejects his or her own unacceptable attributes by ascribing them to objects or persons in the outside world instead. Thus, projection involves projecting[clarification needed] negative qualities onto others, and is a common psychological process.[1][2] Theoretically, projection and the related projective identification reduces anxiety by allowing the unconscious expression of the unwanted unconscious impulses or desires through displacement.[3][not in citation given]