The first studies of emotional deprivation concerned children living in an institution (1–7). Spitz and Wolf (7) studied children in a foundling home where the infants lived in cubicles up to 15 to 18 months of age, completely separated from each other. Their visual radius and locomotion were extremely restricted. During their first few months these infants were breastfed by their mothers. Permanent separation from the mother took place predominantly in the sixth month. After removal of the mother, many of these children developed a syndrome that the authors called anaclitic depression. Beginning with apprehension, sadness, and weeping, the syndrome continued into rejection, withdrawal, loss of appetite, refusal to eat, loss of weight, loss of interest in the outside world, stereotyped movements, dejection, retardation, and finally a condition that could only be described as stuporous. In spite of the fact that hygiene and precautions against contagion were impeccable, the children showed marked susceptibility to infection and illness of every kind. During a follow-up period of two years this group showed a mortality of 37 per cent. Of 21 surviving children still at the institution, only 2 fell within the height range of a normal two-year-old child (6). Only 5 out of 21 were able to walk unassisted. Mental and speech development were extremely retarded. The authors also studied another institution where the infants were less isolated and were cared for by their mothers (delinquent girls). In a number of cases the mother was temporarily removed somewhere between the sixth and eighth month. Some of these children also developed the syndrome of anaclitic depression. After restoration of the love object following approximately three months of absence, the syndrome disappeared. This was in contrast to the cases of longer-lasting separation in the foundling home, where intervention was no longer effective and the syndrome appeared to become irreversible. During a follow-up period of one year not a single child died and motor and mental development were within normal limits. As regards the aetiology of the syndrome, Durfee and Wolf (1), who performed an investigation of institutional care of infants in 1933, already stressed two important factors that were responsible for the psychological injury suffered by these infants: lack of stimulation and absence of the mother. Spitz and Wolf (7) also stressed the importance of free locomotion in the second half-year of life, which they considered to be the most vulnerable age. At that age, motor activity can be used for an attempt to seek replacement for the lost love object. Moreover, it can be argued that in the syndrome of anaclitic depression the acute separation of mother and child is more harmful than mere absence of the mother.