JUVENILE FRIENDS, BEHAVIOR, AND IMMUNE-RESPONSES TO SEPARATION IN BONNET MACAQUE INFANTS

Individual differences in the response to maternal separation in nonhu man primate infants have been attributed to (among other variables) pr esence or absence of processes that may model social support in humans . Alternative attachments to other members of the social group buffer the infant against a depressive response to maternal separation. This hypothesis was tested in a group of bonnet macaques by manipulating th e presence or absence of alternative juvenile attachment figures (frie nds) during separation. Infants who retained such attachments showed f ewer behavioral evidences of depression when separated from their moth ers. These infants without friends also showed changes in lymphocyte a ctivation by mitogens or natural cytotoxicity that were not evident in the infants with juvenile friends. Across all separated infants, natu ral cytotoxicity was positively correlated with juvenile affiliative b ehavior directed toward the infants during the separation. These resul ts support the hypothesis that social support, available from alternat ive attachments, can modulate the response to loss, and can account fo r some of the individual differences seen in these responses. Copyrigh t (C) 1997 Elsevier Science Inc.