Denial
Denial is probably one of the best known defense mechanisms, used often to describe those who seem unable to face reality or admit and obvious truth (i.e. "He's in denial."). Denial is an outright refusal to admit or recognize that something has occurred or is currently occurring. Drug addicts or alcoholics often deny that they have a problem, while victims of traumatic events may deny that the event ever occurred.Denials functions to protect the ego from things that the individual cannot cope with. While this may save us from anxiety or pain, denial also requires a substantial investment of energy. Because of this, other defenses are also used to keep these unacceptable feelings from consciousness.
Repression
Repression is another well-known defense mechanism. Repression acts to keep information out of conscious awareness. However, these memories don't just disappear; they continue to influence our behavior. For example, a person who has repressed memories of abuse suffered as a child may later have difficulty forming relationships.Sometimes we do this consciously by forcing the unwanted information out of our awareness, which is known as suppression, but it is usually believed to occur unconsciously.
Next: Displacement and Sublimation
