In both our own and other species, important, but still poorly understood, relations exist between the body's physiological reaction to stress and the presence of significant social partners. On the one hand, the presence of social partners with which a strong bond has been formed can often reduce the physiological stress response, while on the other, reductions in stress-related hormone levels seem to promote the formation of social bonds. The current project will examine these effects and how they change over the life span as individuals form differing age-specific social relations and undergo normal developmental changes in neuroendocrine activity. These questions will be studied in guinea pigs because of their similarity to primates in the ways that social behavior affects stress hormone levels, and because these questions can be studied with greater experimental control, more economically, and in a reasonable period of time in this rodent species. This project will assess the impact of various social partners throughout the life span on stress hormone levels; examine how this impact varies with normal age-specific changes in social interactions and stress hormone responsiveness; and assess how altering hormone responsiveness affects the formation of adult social bonds. These studies will provide new information on the development of basic biobehavioral processes related to stress and social interactions, and they will provide a unique contribution in their longitudinal approach. The work will also integrate research and undergraduate education by involving promising undergraduates interested in careers in the life sciences in every aspect of the studies.
