Recent theories of nonhuman primate social organization and behavior suggest the existence of two primary modes of attention. In centripetal social groups attention is directed inward toward the group, ultimately to the dominant male. In acentric social groups attention is directed outward toward the surrounding environment. Such fundamental differences in postulated attention structure promote extreme, but predictable, variability in spatial relationships and social organization between primates displaying opposing modes. This difference is tested in two species of Old World monkeys, Mandrillus sphinx and Theropithecus gelada (subfamily Cercopithecinae), and shown to be that individuals in strongly centripetal groups remain closer to their dominant males than individuals in weakly centripetal groups. Correlations with other socioecological factors, including visual attention and body orientation are also demonstrated.