Hormones may infuence both social attachment and reactivity to stress

Abstract

Social bonds are of major importance to survival and reproduction. Socialattachments, and especially pair bonds, provide a sense of safety, reduce anxi-ety or stress, and facilitate sexual and maternal behaviors. However, selectivesocial behaviors, including those that comprise social bonds, are uncommonin laboratory animals. Nonhuman primates and some domestic animals doexhibit selective social behaviors, but are difficult to study in the laboratory.In addition, it is sometimes assumed that the development of selective socialbonds is based on complex or “higher” cognitive processes. For these reasonsthe study of social attachments has remained largely within the domain of social and behavioral sciences.

There is accumulating evidence that biological, and specifically hormonal,processes can be causally important in social behavior in general, and morespecifically in the formation of social attachments. One purpose of this paperis to describe an animal model that is now helping to advance our under-standing of the endocrinology of social attachment. Research in animals hashighlighted the hypothesis that hormones, and specifically oxytocin and vaso-pressin, may act within the nervous system to facilitate social bonding. Socialbonds and other positivesocial experiences may buffer the response to stres-sors and convey a survival advantage. Hormones (especially oxytocin) that arecapable of influencing social bonding also have been implicated in the regula-tion of hypothalamic-pituitary-adrenal (HPA) or “stress” axis.