According to Sigmund Freud, the instinctual and primitive part of the psyche is the id.
Freud’s structural model of personality divides the psyche into three interacting parts: the id, ego, and superego. The id is present from birth and contains basic drives such as hunger, aggression, and sexual desire. It operates according to the pleasure principle, seeking immediate satisfaction without considering consequences or social rules.
The ego develops to negotiate between the id, the external world, and the superego, which represents internalized moral standards. The id is unconscious and is not simply the “bad” part of a person; Freud regarded it as the source of fundamental psychological energy and motivation.
A common mix-up is confusing the id with the ego. The ego is the reality-oriented mediator, while the id is impulsive and unconcerned with reality. Freud famously described the id as the deepest, least accessible part of personality.