Maternal separation in bonnet monkey infants: altered attachment and social support.

Maternal separation in young pigtail (M. nemestrina) monkeys results in an agitation-depression reaction that is a useful animal model of the behavioral and physiological consequences and separation and loss experiences in humans. In this study, 5 social-group-living bonnet (M. radiata) monkey infants were separated from their mothers for 4 days, and behavioral, physiological, and sleep-pattern changes were monitored. Behavioral and physiological changes were consistent with an agitation reaction. There was evidence of depression in both behavioral and physiological measures; these changes were not as pronounced as in pigtail infants, however. All infants were adopted by another adult female during separation. Our findings suggest that, in bonnet monkey infants, adoption by a female within the social group ameliorates the response to loss.