By focusing on peace, Glowacki provides a fresh perspective on warfare. Why did humans evolve peace? Other animals aggregate peacefully when resources are not economically defendable. The human capacity for peace may arise from two key factors: Multilevel societies and psychology shaped by within-group exchanges, which may have begun when tools enabled hominins to extract foods, including tubers and roots.

Peace is a hallmark of human societies. However, certain ant species engage in long-term intergroup resource sharing, which is remarkably similar to peace among human groups. We discuss how individual and group payoff distributions are affected by kinship, dispersal, and age structure; the challenges of diagnosing peace; and the benefits of comparing convergent complex behaviours in disparate taxa.

There is a well-entrenched schism on the frequency, intensity, and evolutionary significance of warfare among hunter-gatherers compared with large-scale societies. To simplify, Rousseauians argue that warfare among prehistoric and contemporary hunter-gatherers was nearly absent and, if present, was a late cultural invention. In contrast, so-called Hobbesians argue that violence was relatively common but variable among hunter-gatherers. To defend their views, Rousseauians resort to a variety of tactics to diminish the apparent frequency and intensity of hunter-gatherer warfare. These tactics include redefining (...) war, censoring ethnographic accounts of warfare in comparative analyses, misconstruing archaeological evidence, and claiming that outside contact inflates the intensity of warfare among hunter-gatherers. These tactics are subject to critical analysis and are mostly found to be wanting. Furthermore, Hobbesians with empirical data have already established that the frequency and intensity of hunter-gatherer warfare is greater compared with large-scale societies even though horticultural societies engage in warfare more intensively than hunter-gatherers. In the end I argue that although war is a primitive trait we may share with chimpanzees and/or our last common ancestor, the ability of hunter-gatherer bands to live peaceably with their neighbors, even though war may occur, is a derived trait that fundamentally distinguishes us socially and politically from chimpanzee societies. It is a point often lost in these debates. (shrink)

Michael Tomasello ( 2016 ) prominently defends the view that there are uniquely human capacities required for shared intentions, therefore great apes do not share intentions. I show that these uniquely human capacities for abstraction are not necessary for shared intentionality. Excluding great apes from shared intentions because they lack certain capacities for abstraction assumes a specific interpretation of shared intentionality, which I call the Roleplaying Model. I undermine the necessity of abstraction for shared intentionality by presenting an alternative model (...) of shared intentionality, which I call the Normative Model. It is a modification of Margaret Gilbert’s ( 2013 ) Plural Subject theory, which I modify such that it is, in principle, compatible with nonhuman shared intentionality. To do this, I substitute Gilbert’s account of obligation for Kristin Andrews’ ( 2020 ) account of animal social norms. In this Normative Model, uniquely human capacities for abstraction are not required for shared intentionality. By undermining the necessity of uniquely human abstraction, I make cases of prima-facie cooperation in chimpanzees plausible instances of shared intentionality. The Roleplaying Model’s denial of nonhuman shared intentionality creates a problem insofar as apparent shared intentional activity cannot be fully analyzed. The Normative Model resolves this problem. (shrink)