We have presented some of the observational findings from a study of institutionalized infants deprived of adequate human contact. These findings demonstrate that in these infants various parts of the apparatus of the ego mature when they would normally be expected to, but are not integrated or put to use in a normal fashion in the service of the infant's adaptation to his environment. In other words, the maturational sequence and timetable are not disturbed, but development is retarded.

We have described the institutional infant's behavior with toys, his investment in them, and his lack of initiative in approaching and exploiting them. The institutional infant's inability in the second half of the first year to solve the problem of finding the hidden toy is interpreted as indicating a deficit in the type of secondary-process thinking necessary for problem solving.