Social Recovery by Isolation-Reared Monkeys

Abstract

Total social isolation of macaque monkeys for at least the first 6 months of life consistently produces severe deficits in virtually every aspect of social behavior. Experiments designed to rehabilitate monkeys reared in isolation are described. While young isolates exposed to equal-age normal peers achieved only limited recovery of simple social responses, some mothers reared in isolation eventually exhibited acceptable maternal behavior when forced to accept infant contact over a period of months, but showed no further recovery; isolate infants exposed to surrogates were able to develop crude interactive patterns among themselves. In contrast to the above results, 6-month-old social isolates exposed to 3-month-old normal monkeys achieved essentially complete social recovery for all situations tested. It is postulated that social stimulation that both permits subjects to achieve contact acceptability and provides an interactive medium conducive to gradual development of sophisticated social behaviors will result in almost complete recovery of social capabilities previously obliterated by rearing in isolation.Social isolation has long been identified as a powerful precipitating agent in disruption of normal social development in human beings. While ethical considerations and practical constraints have obviously restricted controlled scientific study of isolation with human subjects, it has been possible to systematically investigate the effects of total social deprivation upon closely related, nonhuman, primate species. The unequivocal finding of numerous researches on macaque monkeys has been that total social isolation for at least the first 6 months of life enormously damages or destroys subsequent social and sexual behavioral capabilities (1-3). Monkeys so reared were grossly incompetent in interactions with socially normal age-mates. As infants and adolescents, they failed to initiate or reciprocate the play and grooming behaviors characteristic of their peers. As adults, these monkeys consistently exhibited abnormal sexual, aggressive, and maternal behaviors.It is clear that early social deprivation is an enormously effective procedure for the production of psychopathological behavior patterns. Less well known is the degree to which social behaviors can be recovered after early social isolation. The data that follow indicate that social deprivation early in life does not necessarily produce irreversible behavioral deficits, and that rehabilitation of varying extent can be effected via judiciously chosen experimental procedures.Several pairs of rhesus monkeys reared for the first 6 months of life in total social isolation chambers (4) were tested on a daily basis in a social playroom (4) with pairs of socially competent age-mates. In comparison to the normal stimulus animals, the isolates were clearly inferior on virtually every behavioral measure throughout the 8-month testing period.1534

Short-term benefits, but transgenerational costs of maternal loss in an insect with facultative maternal care

“…Females reared without mothers abandoned their juveniles for longer and provisioned them with less food than females reared with tending mothers. To the best of our knowledge, the long-term, negative effects of maternal loss on the expression of maternal care have only been reported in altricial vertebrates [8][9][10]13]. In these species, the effects of maternal loss typically result from a disrupted learning process [30] and/or from induced hormonal/neurobiological changes during juvenile development.…”

Stereotypies: a critical review

“…Conversely, deprivation stereotypies are not always irreversible; deprived rhesus monkeys have been cured through the use of infant 'therapists' (e.g. Harlow & Suomi 1971), and the stereotypies of isolation-reared chimpanzee_s are reduced, at least in the short-term, by the provision of objects to manipulate (Berkson et al 1963).…”

“…For example, stereotypies may be the norm for a captive population. When Harlow & Suomi (1971) wrote of 'normal' stereotypy levels, they meant those of laboratory monkeys that had been reared in a group rather than in isolation. However, the majority of authors (e.g.…”

Allostatic load and biological anthropology

“…Early research on stressors in nonhuman primates focused mainly on sequela of maternal separation and social isolation in deprived infants (Harlow & Suomi, 1971;Harlow et al, 1965). Even small alterations in species-typical rearing conditions were observed to have adverse long-term impacts on stress physiology and emotionality among nonhuman primates (Gunnar & Quevedo, 2007;Sanchez, 2006 (Levine & Wiener, 1988), ACTH (Clarke & Boinski, 1995), norepinephrine (Higley, Hasert, Suomi, & Linnoila, 1991), and immune response (Boccia, Laudenslager, & Reite, 1995;Coe, 1993;Gorman, Mathew, & Coplan, 2002;Reite, Harbeck, and Hoffman, 1981).…”