This book provides a comprehensive look at nonhuman primate social inequalities as models forhealth differences associated with socioeconomic statusin humans. The benefit of the socially-housed monkey model is that it provides the complexity of hierarchical structure and rank affiliation, i.e. both negative and positive aspects of social status. At the same time, nonhuman primates are moreamenableto controlled experiments and more invasive studies that can be usedin human beingsto examine the effects of low status on brain development, neuroendocrine function, immunity, and eating behavior. Because all of these biological and behavioral substrates form the underpinnings of human illness, and are likely shared among primates, the nonhuman primate model can significantly advance our understanding of the best interventions in humans.