Introduction

Primatologists have long been fascinated by the dominance hierarchies of their study subjects. A number of early researchers attributed what was, in retrospect, an inappropriate power to an animal's rank in predicting its reproductive success, degree of attractivity to the opposite sex, willingness to defend other individuals against predators, and so on. Many of these misconceptions were clarified with the emergence of new theoretical constructs, such as the recognition of female choice, of alternative competitive strategies among individuals, or the importance of kin-based models of natural selection. In the wake of some of this early overenthusiasm for the explanatory power of rank, a number of individuals questioned the validity of the rank concept – whether such dyadic assymetries actually occur under most ecological conditions (e.g., Rowell, 1974), and whether the animals themselves “understood” rank in a meaningful way (as opposed to a hierarchy merely being an artificial construct projected by human observers) (e.g., Bernstein, 1981).

Despite these critiques, dominance hierarchies have remained close to the hearts of many primatologists, and are thought to occur among many species and to provide a meaningful way to understand individual differences in the experiences and quality of life of non-human primates. Out of this has emerged a considerable number of studies built around the premise that rank in such hierarchies helps to explain individual differences in the physiology of primates, with important implications for understanding disease patterns and differential fitness.