This project addresses fundamental questions in animal behavior and anthropology regarding the evolution of sociality and cooperation in primates. Multilevel societies are the most complex and least understood of all primate social systems. They are characterized by a hierarchical structure with nuclear one-male units (OMUs) embedded within bands and often all-male units (AMUs) at the periphery of the band. This type of social organization has been documented in several Old World primate species such as hamadryas baboons and snub-nosed monkeys (Rhinopithecus spp.). Also humans live in hierarchically organized societies with conjugal units as the building blocks. In order to better understand the behavioral mechanism underlying tolerance and co-existence among OMUs in a multilevel society and the role of kinship in promoting such a system, we plan to investigate inter-unit and inter-male relations in a provisioned band of golden snub-nosed monkeys (Rhinopithecus roxellana) at Shennongjia Nature Reserve in Hubei, China. The band contains four OMUs and one AMU. The first goal will be to record the spatial arrangements of units in the band via association indices and the nature of inter-unit relationships among age-sex classes. We will use social network theory to delineate clusters within the society and assess the strengths of association among units. The second goal will be to characterize and quantify the degree of cooperation among unit males in the band, especially in the context of group vigilance. The third goal will be to estimate microsatellite-based relatedness among males of different units to see if inclusive fitness benefits crystallize hierarchical social structuring along genetic lines. This research will have the potential to contribute to larger scale comparative studies of Rhinopithecus/primate behavior at several locations in China and has important implications for an understanding of human social evolution.