A comparison was made between the behaviour of 61 severely socially deprived children and 41 controls during a psychiatric screening session. Ages ranged from 1.5 to 12 years. The occurrence of directly observable ethological categories of social interaction, activity and play was determined by use of a keyboard. Problem children differed from controls in most measurements relevant to social orientation of the child to the psychiatrist ; however, there was much overlap. Combination of seven objectively defined categories resulted in a parameter with greater distinction, indicating a strongly reduced degree of social orientation in many deprived children. In contrast, spontaneity in con-versation did not consistently differ from controls. Motor activity was more variable than in controls ; some deprived children were overactive, some others were very passive. Social orientation during psychiatric investigation appears to be a commonly found characteristic of deprivation. It is discussed in how f ar deviations in social orientation are related to a number of other disorders known to be associated with deprivation.