Psychological defense mechanisms are forms of self-deception and self-protection used to avoid or cope with the anxiety that occurs when confronting one's weaknesses and mistakes. Some of the most common forms of defense mechanisms are denial, repression, regression, projection and displacement.
Denial is an attempt to protect self-esteem by refusing to acknowledge the reality of a situation or admit the truth about one's behavior. Repression is forgetting about a negative experience or feeling. A person who reverts back to a younger stage of development is displaying regression. Examples of regression are road rage temper tantrums and excessive dependency on others to meet physical or emotional needs.
A person who attributes his own perceived faults and feelings to others, because to recognize them as their own causes painful ego deflation, is using projection. Displacement is the shifting of negative feelings away from the original or causative force and placing them onto another source that is perceived as less threatening or harmful. A classic example is having a bad day at work and taking it out on the children or pets upon arriving home.
Other psychological defense mechanisms include reaction formation, intellectualization, rationalization and sublimation, which is transforming unacceptable impulses into socially accepted or productive actions.