• In an attempt at social rehabilitation, chlorpromazine was given to three groups of rhesus monkeys that had been confined to the vertical chamber apparatus early in their development. Previous studies have shown that such periods of deprivation produce severe deficits in social behavior. There were no substantial beneficial effects of chlorpromazine treatment; however, there was a notable amount of spontaneous improvement seen in all three groups. We discuss these data in terms of their implications for the use of the vertical chamber as a tool in experimental research of psychopathological disorder.