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Novak, M. A. Social recovery of monkeys isolated for the first year of life: II. Long-term assessments. Developmental Psychology, 15(2), 50-61.
Previous research (S. J. Suomi and H. F. Harlow, 1972; M. A. Novack and H. F. Harlow, 1975) demonstrated that the isolation syndrome in rhesus monkeys could be reversed by exposing isolate-reared monkeys to younger, "therapist" monkeys. However, estimates of social recovery were limited because the isolate monkeys were not tested with age-mates and the observations of these monkeys were restricted to the early juvenile period. The present 3 experiments with 15 rhesus monkeys demonstrated that 3-yr-old rehabilitated isolates could exhibit appropriate social behaviors to age-mate Ss, but only after further treatment. Isolates were initially deficient to age- mate controls in their social repertoire and were attacked in social encounters with the normal Ss. Isolate behavior did not change following 10 wks of visual exposure to the age-mates, but it did improve substantially after the isolates were housed permanently as a group of 4 rather than individually. Tests with another group of age- mate controls and with monkey infants confirmed the newly acquired social competency of the isolates and their ability to interact appropriately and nonaggressively with young animals. The significance of these findings for theories of social development is discussed. (16 ref) (PsycINFO Database Record (c) 2003 APA, all
Novak, M. A., & Harlow, H. F. Social recovery of monkeys isolated for the first year of life: I. Rehabilitation and therapy. Developmental Psychology, 11(4), 453-465.
Previous research demonstrated that 12 mo of total social isolation initiated at birth produced severe and seemingly permanent social deficits in rhesus monkeys. Such monkeys exhibited self-clasping, self-mouthing, and other stereotypic, self-directed responses. Recent research has indicated that 6-mo -isolated monkeys could develop social behaviors if exposed to younger, socially unsophisticated "therapist" monkeys. In the present experiment, 4 12 -mo isolate- reared monkeys developed appropriate species-typical behavior through the use of adaptation, self-pacing of visual input, and exposure to 4 younger "therapist" monkeys. Adaptation enabled the isolate Ss to become familiar with their postisolation environment, while self- pacing facilitated their watching the therapist Ss' social interactions. The isolates showed a marked decrease in self-directed behaviors following extensive intimate contact with the therapists. Species-typical behaviors significantly increased during this period, so that the isolate behavioral repertoire did not differ substantially from the therapist behavioral repertoire by the end of the therapy period. Results clearly fail to support a critical period for socialization in the rhesus monkey, and an alternative environment-specific learning hypothesis is proposed. (25 ref) (PsycINFO Database Record (c) 2003 APA, all rights reserved)