defence mechanism

Level 2 Defence Mechanisms
These mechanisms are often present in adults and more commonly present in adolescence. These mechanism lessen distress and anxiety provoked by threatening people or by uncomfortable reality. People who excessively use such defences are seen as socially undesirable in that they are immature, difficult to deal with and seriously out of touch with reality. These are the so-called "immature" defences and overuse almost always lead to serious problems in a person's ability to cope effectively. These defences are often seen in severe depression, personality disorders. In adolescence, the occurrence of all of these defences is normal.
These include:
Fantasy: Tendency to retreat into fantasy in order to resolve inner and outer conflicts
Projection: Projection is a primitive form of paranoia. Projection also reduces anxiety by allowing the expression of the undesirable impulses or desires without becoming consciously aware of them; attributing one's own unacknowledged unacceptable/unwanted thoughts and emotions to another; includes severe prejudice, severe jealousy, hypervigilance to external danger, and "injustice collecting". It is shifting one's unacceptable thoughts, feelings and impulses within oneself onto someone else, such that those same thoughts, feelings, beliefs and motivations as perceived as being possessed by the other.
Hypochondriasis: The transformation of negative feelings towards others into negative feelings toward self, pain, illness and anxiety
Passive aggression: Aggression towards others expressed indirectly or passively
Acting out: Direct expression of an unconscious wish or impulse without conscious awareness of the emotion that drives that expressive behavior

Level 3 Defence Mechanisms
These mechanisms are considered neurotic, but fairly common in adults. Such defences have short-term advantages in coping, but can often cause long-term problems in relationships, work and in enjoying life when used as one's primary style of coping with the world.
These include:
Displacement: Defence mechanism that shifts sexual or aggressive impulses to a more acceptable or less threatening target; redirecting emotion to a safer outlet; separation of emotion from its real object and redirection of the intense emotion toward someone or something that is less offensive or threatening in order to avoid dealing directly with what is frightening or threatening
Dissociation: Temporary drastic modification of one's personal identity or character to avoid emotional distress; separation or postponement of a feeling that normally would accompany a situation or thought.
Intellectualization: A form of isolation; concentrating on the intellectual components of a situations so as to distance oneself from the associated anxiety-provoking emotions; separation of emotion from ideas; thinking about wishes in formal, affectively bland terms and not acting on them; avoiding unacceptable emotions by focusing on the intellectual aspects
Reaction Formation: Converting unconscious wishes or impulses that are perceived to be dangerous into their opposites; behavior that is completely the opposite of what one really wants or feels; taking the opposite belief because the true belief causes anxiety. This defence can work effectively for coping in the short term, but will eventually break down.
Repression: Process of pulling thoughts into the unconscious and preventing painful or dangerous thoughts from entering consciousness; seemingly unexplainable naivete, memory lapse or lack of awareness of one's own situation and condition; the emotion is conscious, but the idea behind it is absent
Sublimation: Transformation of negative emotions or instincts into positive actions, behavior, or emotion; acting out unacceptable impulses in a socially acceptable way; refocusing of psychic energy away from negative outlets to more positive ones; sublimation is the process funneling the unacceptable into social useful achievements. Sublimation is instrumental to developing culture and civilization. Psychoanalysts often refer to sublimation as the only truly successful defence mechanism.

http://en.wikipedia.org/wiki/Defense_mechanism