A conception of the ego as a decisive agency of the mind was the point of departure of psychoanalytical ego psychology, which teaches that the ego may have a normal development (the approximate meaning of "normal" being "socially adapted"). According to Heinz Hartmann, adaptation is an essential task of the ego, one performed in a conflict-free, autonomous dimension of the ego distinct from the dimension of the ego dominated by the instincts. But this independent domain of the ego is liable to suffer many sorts of damage, whether at the beginning of life or later on. The most recent research on infancy has shown that one of the causes of such damage is a lack of adequate bonds with the mother or mother substitute. Genetic causes no doubt also play a part, but in this area the state of our knowledge is still rudimentary.

Apart from bonds with the mother or mother substitute, there are particular social conditions that can inflict...