Early social relationships: a psychobiologist's view.

This article outlines a strategy for studying early social relationships in relatively simple animal model systems. It describes some of the differences in approach between neuroscientists and human developmentalists in dealing with the same research problems. These ideas are then illustrated in work from our laboratory on the processes of early social attachment in young rats and on their responses to separation from their mothers. We have found evidence for a novel mechanism by which the mother appears to be a regulator of physiological and behavioral systems of the infant so that many of the prolonged responses to separation represent withdrawal or release phenomena. Finally, I will describe some surprising results from our studies on the organization of nursing that reveal an unexpected degree of synchrony and reciprocity in this apparently simple interaction that is so basic to being a mammal.