Chapter 6 - Abnormal Behavior in Nonhuman Primates and Models of Development

Abstract

This chapter explains abnormal behavior in nonhuman primates and identifies factors that may contribute to the development of abnormal behavior and draws parallels between human and nonhuman primates with respect to these phenomena. Macaques are a genus of Old World monkeys that can be found in a wide range of different environments, including remote forests, agricultural areas, small towns, and even large cities. Abnormal behavior in nonhuman primates often takes the form of stereotypic behavior, defined as iterative, highly ritualized motor actions which appear to have no identifiable biological function. It is now well established that there are marked individual differences in reactivity among nonhuman primates when animals are exposed to novel situations or to relatively minor changes in their social or physical environment. A variety of factors have been proposed to account for the development of abnormal behavior in monkeys. These factors range from specific environmental situations to neurochemical/cytoarchitectural abnormalities in the brain. A long-standing view is that abnormal behavior in macaques emerges as a result of socially inadequate early rearing experiences. Currently, there is no well-established link between nonhuman primate stereotypies and models of psychological disease. But the presence of stereotypic patterns of behavior may reflect several underlying psychological dysfunctions including anxiety and impulse control disorders that are most likely elicited in genetically vulnerable individuals by exposure to stressful environments at crucial periods in development.