Introduction
Personality is a relatively stable pattern of thinking, feeling and behaving that distinguishes one person from another and persists across situations. Personality theories try to explain its structure, its origin and its development. They matter in medicine because personality influences how people respond to illness, adhere to treatment and cope with stress.
Psychoanalytic theory
- Sigmund Freud proposed that behaviour is driven by unconscious conflicts between three structures: the id, which seeks pleasure and is present from birth; the ego, which mediates reality; and the superego, which holds moral standards.
- Freud described the mind as conscious, preconscious and unconscious, and he saw the id, ego and superego as functional roles rather than physical parts of the brain. He proposed psychosexual stages (oral, anal, phallic, latency and genital), with fixation at a stage shaping adult character.
- Defence mechanisms protect the ego from anxiety. The main ones are repression, denial, projection, displacement, reaction formation, regression and sublimation.
- The theory is difficult to test empirically, and many of its claims are no longer accepted, although its concepts of unconscious processes and defence remain in clinical use.