The id forms the instinctual, mostly psychophysiological basis of the whole structure. The ego, which is mostly based on the id, is the part that comes in contact with the external world. It is formed by the process of contact with and adaptation to the environment, mostly the parents. The superego is a structure that forms the apex of the psychic structure and includes the ideals of the personality and the principles of judgment. It is the seat of what is customarily called the conscience. It develops mainly by internalizing and identifying with the prohibitions, rules, values, and preferences of the parents and society at large. The sequence of development in the Diamond Approach follows the line of regression of this structure. The part last formed and organized, the superego, becomes the first part the individual deals with and understands. Then the ego becomes the focus, and finally the id itself with its instincts and drives.

We now come to the last and deepest structure of the personality, which Freud called the id. The id is the sector of the personality that is most primitive, closest to the biological roots, and that contains the instincts and their energies and drives. The instincts and their drives are still the least understood part of depth psychology. The id, however, as Freud had already pointed out, is really the basis and the ground for the whole personality. The instincts and their drives are usually the categories that people question least. People are driven by their instincts, and this drivenness is seen as the natural course and therefore is not questioned. People are usually not interested in being free from the deep influences of their instincts. The instincts are so deep and basic and determine the personality and its life to such an extent that it does not even occur to the individual to wonder whether it is possible to be free from instinct.