A number of studies in nonhuman primates have documented the relationship between dominance ranking in social groups and a number of behavioral, neurochemical, and hormonal parameters. Studies in rodents have indicated that dominance related behaviors have important influences on immune regulation. For nonhuman primates, little is known with regard to the relationship between dominance-related behavior and immune regulation. Herein we propose to investigate the influence of dominance- related behavior on immune regulation in socially-housed adult macaque monkeys. Multiple in vitro and in vivo measures of humoral and cellular immune response will be assessed in 1) monkeys living in established social groups, 2) monkeys introduced into established social groups, and 3) monkeys undergoing environmental change (clumped versus widely dispersed food resources) known to elevate levels of social group dominance- related behaviors. It is expected that in stable, established groups, dominance rank will have little influence on immune regulation. However, the introduction of a stressor such as a strange monkey or clumped food resources, will escalate dominance-related behaviors and also impact on the immune response of the monkeys. The nature of the modulation of the immune response will be a function of the monkey's relative social standing. These studies have important implications for a better understanding of the relationships between dominance-related behaviors and immune regulation, specifically, and behavior and health, generally.