The problem investigated was whether one experience of profound environmental deprivation early in development would influence the response of rhesus monkeys to a subsequent period of deprivation.
Subjects with a history of previous vertical chamber confinement were tested 1½ years later and compared with control subjects with no prior history of environmental deprivation. Monkeys with a history of early chamber confinement exhibited residual effects 1½ years after their initial experience but before reentering the chamber. Furthermore, the current chambering experience had a significant impact in terms of producing decreased environmental activity and increased passivity.
Effects of the current chambering experience occurred whether or not individual subjects had had a prior experience. These data contrast with previous studies which indicate prior separation to be a high risk-predisposing event in rhesus monkeys.
McKinney WT, Kliese KA, Suomi SJ, Moran EC. Can Psychopathology Be Reinduced in Rhesus Monkeys?An Experimental Investigation of Behavorial Sensitization. Arch Gen Psychiatry. 1973;29(5):630-634. doi:10.1001/archpsyc.1973.04200050043007