Projection lowers our anxiety by letting our instincts and desires get expressed without becoming consciously aware of them. We take our own unacceptable or unwanted thoughts and emotions and place them onto another person, perhaps blaming them, shaming them or otherwise dispensing with that in ourselves which we do not like.
This is a defense mechanism which truly highlights how much personal boundaries are involved in our defenses, by way of the boundary anatomy” which we have described as “holes” in the boundary.
Imagine how terrible in would be to come face to face with one’s own jealousy, prejudice, or other ugliness and to realize that what you are feeling is simultaneously unacceptable to you.
Such a person who uses this defense often may do "injustice collecting", all with the aim of shifting one's unacceptable thoughts, feelings and impulses onto someone else, so that those same thoughts, feelings, and beliefs that one does not want to take ownership of can be blamed on others leaving one more free of anxiety and conflict.