1. generally, the physiological, psychological, and sociocultural processes by which a person attains status as an individual human being and exerts himself or herself as such in the world.

2. in the psychoanalytic theory of Carl Jung, the gradual development of a unified, integrated personality that incorporates greater and greater amounts of the unconscious, both personal and collective, and resolves any conflicts that exist, such as those between introverted and extraverted tendencies.

3. a phase of development, occurring between the 18th and 36th months, in which infants become less dependent on their mothers and begin to satisfy their own wishes and fend for themselves. [postulated by Hungarian-born U.S. child psychoanalyst Margaret Schönberger Mahler (1897–1985)]