A term used in psychoanalytic theory to describe the process of returning to a childhood level of behaviour, such as thumb-sucking.
n. (in psychiatry) reversion to a more immature level of functioning. The term may be applied to the state of a patient in hospital who becomes incontinent and demanding. It may also be applied to a single psychological function; for example, psychoanalysts speak of the *libido regressing to an early stage of development.
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