This chapter analyzes predictors of sociopolitical behavior in nonhuman primates, concentrating on within-group conflict frequencies among various taxa. Within the past 70 years, primatologists and evolutionary researchers have repeatedly identified associations between socioecological factors and the rise of complex cognition in nonhuman primates. The presence of sophisticated sociopolitical dynamics in nonhuman primates provided the empirical foundation for the Machiavellian Intelligence Hypothesis (Byrne, 2018), wherein fitness outcomes were attributable to social abilities instead of merely to physical force during cooperative and agonistic interactions. Following this literature, several behavioral ecologists and primatologists have developed metrics destined to capture the degree of cooperation and competition within primate societies and their corresponding morphological and cognitive correlates. The review of this literature, along with a series of novel analyses, provides comparative evidence of political behavior in nonhuman primates, laying the foundation for subsequent chapters on the evolution of human political nature. Even more than their ape and hominid ancestors, Homo sapiens have a particular evolutionary history, relevant to intelligence and social organization, that bears on the capacity to act politically. Most broadly, this chapter provides evidence supportive of the following conclusion: Humans are the most extreme case within a phylogenetic lineage already disposed toward Machiavellian intelligence and complex, violent social dynamics.