Recent scientific advances in our understanding of the forces shaping social behavior have been driven by growing appreciation of the influence of hormones, especially the neuropeptides oxytocin (OXT) and arginine vasopressin (AVP). These hormones are being implicated as essential mechanisms in shaping a range of affiliative and aggressive social relationships and behavior, including pair-bonding, territoriality, parenting, and cooperation. Fully comprehensive understanding of how these hormones function could provide not only knowledge of the organization of social life, but also therapeutic benefits to organisms, including humans, with social impairments. Research into oxytocin and vasopressin utilizing rodent models has begun to suggest potential treatments for several human conditions, including autism spectrum disorders, social anxiety, and schizophrenia. While these studies provide essential data on the roles of hormones such as OXT and AVP, they are limited by the fact that they focus on animals with social systems characterized by less complexity and richness, relative to those of our species. With the goal of more thoroughly investigating the roles that these hormones play in mediating complex social behavior, this dissertation research by doctoral student Daniel Coppeto (under the supervision of Dr. James Rilling, Emory University) will utilize anthropological and neuroscientific approaches to linking hormones and social behavior in two primates with complex, yet differing social systems.
This project will advance the study of how oxytocin and vasopressin mediate complex social relationships by investigating the roles that these hormones play in the social lives of two types of baboons with vastly differing societies, the hamadryas and the anubis baboon. Like humans, baboons display a range of sociality and intricate social structures, and as such, present a unique opportunity to employ an animal model with enhanced relevance to understanding the phenomenon in our own species. To test the hypothesis that these contrasting societies can be understood through assessing the roles of oxytocin and vasopressin, this project will first collect biological samples to measure oxytocin and vasopressin levels utilizing enzyme immunoassays, comparing these between the two subspecies. By then linking the hormonal data to observations of social behavior of the subjects within social groups of each subspecies, the project will provide a highly contextualized understanding of how OXT and AVP mold sociality. These will be complemented through neurobiological examination of how oxytocin and vasopressin receptors are distributed in the brain, as differences in the pattern of brain hormone receptors are a common avenue by which these hormones may affect behavior.
The results of this research will have impacts across several dimensions, from basic science and education, to potential therapeutic translation. While this project will show how oxytocin and vasopressin are integral to shaping primate societies, it also will demonstrate in appropriate animal models how these forces are capable of influencing our own behavior. Likewise, an analysis of how these hormones operate in primates will provide insight into how they can potentially be refined for usage in therapy for a range of human social disorders.
