From a clinical standpoint, it is crucial to distinguish between two stages of maturity.
Mature defense mechanisms, also known as repression, require a well-developed personality. Three examples: Repression, in which something is pushed into the unconscious. Reaction formation, in which a frowned-upon impulse is reversed into its opposite. Displacement, in which anger is directed not at the rival but at the weaker person.
Early defense mechanisms, also known as splitting, develop earlier and distort perception more significantly. For example: splitting, in which people appear alternately as either entirely good or entirely bad; projection, in which one’s own traits are attributed to others; and projective identification. These are often accompanied by structural impairments go hand in hand.
Both forms coexist. Under stress, more mature defense mechanisms may be temporarily abandoned in favor of earlier ones. In therapy, this is addressed through Confrontation. From a therapeutic perspective, the focus is on making defenses unnecessary, not on “de-training” them: Defenses become unnecessary once the underlying conflict has been resolved or, in the case of early defenses, once the missing skills have developed.