Why me? -- Sticks and stones -- Hammer of God -- God is great -- The problem of atheists -- Guardian angels -- Nations under God -- God knows.

Evolution of Human Behavior is the first text to synthesize and compare the major proposals for human behavioral evolution from an anthropological perspective. Ideal for courses in the evolution of human behavior, human evolutionary ecology, evolutionary psychology, and biological anthropology, this unique volume reviews a wide array of approaches on how and why humans evolved behaviorally.

_ Convention_ was immediately recognized as a major contribution to the subject and its significance has remained undiminished since its first publication in 1969. Lewis analyzes social conventions as regularities in the resolution of recurring coordination problems-situations characterized by interdependent decision processes in which common interests are at stake. Conventions are contrasted with other kinds of regularity, and conventions governing systems of communication are given special attention.

Political disintegration is a persistent feature of world history. The Collapse of Complex Societies, though written by an archaeologist, will therefore strike a chord throughout the social sciences. Any explanation of societal collapse carries lessons not just for the study of ancient societies, but for the members of all such societies in both the present and future. Dr. Tainter describes nearly two dozen cases of collapse and reviews more than 2000 years of explanations. He then develops a new and far-reaching (...) theory that accounts for collapse among diverse kinds of societies, evaluating his model and clarifying the processes of disintegration by detailed studies of the Roman, Mayan and Chacoan collapses. (shrink)

Despite wide acceptance that the attributes of living creatures have appeared through a cumulative evolutionary process guided chiefly by natural selection, many human activities have seemed analytically inaccessible through such an approach. Prominent evolutionary biologists, for example, have described morality as contrary to the direction of biological evolution, and moral philosophers rarely regard evolution as relevant to their discussions. -/- The Biology of Moral Systems adopts the position that moral questions arise out of conflicts of interest, and that moral systems (...) are ways of using confluences of interest at lower levels of social organiation to deal with conflicts of interest at higher levels. Moral systems are described as systems of indirect reciprocity: humans gain and lose socially and reproductively not only by direct transactions, but also by the reputations they gain from the everyday flow of social interactions. -/- The author develops a general theory of human interests, using senescence and effort theory from biology, to help analye the patterning of human lifetimes. He argues that the ultimate interests of humans are reproductive, and that the concept of morality has arisen within groups because of its contribution to unity in the context, ultimately, of success in intergroup competition. He contends that morality is not easily relatable to universals, and he carries this argument into a discussion of what he calls the greatest of all moral problems, the nuclear arms race. (shrink)

The 'Evolution of Cooperation' addresses a simple yet age-old question; If living things evolve through competition, how can cooperation ever emerge? Despite the abundant evidence of cooperation all around us, there existed no purely naturalistic answer to this question until 1979, when Robert Axelrod famously ran a computer tournament featuring a standard game-theory exercise called The Prisoner's Dilemma. To everyone's surprise, the program that won the tournament, named Tit for Tat, was not only the simplest but the most "cooperative" entrant. (...) This unexpected victory proved that cooperation - one might even say altruism - is mathematically possible and therefore needs no hidden hand or divine agent to create and sustain it. A great roadblock to the understanding of all sorts of behavior was at last removed. The updated edition includes an extensive new chapter on cooperation in cancer cells and among terrorist organizations. (shrink)

A model is presented to account for the natural selection of what is termed reciprocally altruistic behavior. The model shows how selection can operate -against the cheater (non-reciprocator) in the system. Three instances of altruistic behavior are discussed, the evolution of which the model can explain: (1) behavior involved in cleaning symbioses; (2) warning cries in birds: and (3) human reciprocal altruism. Regarding human reciprocal altruism, it is shown that the details of the psychological system that regulates this altruism can (...) be explained by the model. Specifically, friendship,d islike, moralistic aggression, gratitude, sympathy, trust, suspicion, trustworthiness, aspects of guilt, and some forms of dishonesty and hypocrisy can be explained as important adaptations to regulate the altruistic system. Each individual human is seen as possessing altruistic and cheating tendencies, the expression of which is sensitive to developmental variables that were selected to set the tendencies at a balance appropriate to the local social and ecological environment. (shrink)

Early reviewers describe this magisterial study as a "hominids-to-guillotines chronicle of humanity's attempts to build strong, accountable governments", "nothing less than a unified theory of state formation," and "that rare work of history with up-to-the-minute relevance.".

The transfer of food among group members is a ubiquitous feature of small-scale forager and forager-agricultural populations. The uniqueness of pervasive sharing among humans, especially among unrelated individuals, has led researchers to evaluate numerous hypotheses about the adaptive functions and patterns of sharing in different ecologies. This article attempts to organize available cross-cultural evidence pertaining to several contentious evolutionary models: kin selection, reciprocal altruism, tolerated scrounging, and costly signaling. Debates about the relevance of these models focus primarily on the extent (...) to which individuals exert control over the distribution of foods they acquire, and the extent to which donors receive food or other fitness-enhancing benefits in return for shares given away. Each model can explain some of the variance in sharing patterns within groups, and so generalizations that ignore or deny the importance of any one model may be misleading. Careful multivariate analyses and cross-cultural comparisons of food transfer patterns are therefore necessary tools for assessing aspects of the sexual division of labor, human life history evolution, and the evolution of the family. This article also introduces a framework for better understanding variation in sharing behavior across small-scale traditional societies. I discuss the importance of resource ecology and the degree of coordination in acquisition activities as a key feature that influences sharing behavior. (shrink)

We develop a cultural evolutionary theory of the origins of prosocial religions and apply it to resolve two puzzles in human psychology and cultural history: (1) the rise of large-scale cooperation among strangers and, simultaneously, (2) the spread of prosocial religions in the last 10–12 millennia. We argue that these two developments were importantly linked and mutually energizing. We explain how a package of culturally evolved religious beliefs and practices characterized by increasingly potent, moralizing, supernatural agents, credible displays of faith, (...) and other psychologically active elements conducive to social solidarity promoted high fertility rates and large-scale cooperation with co-religionists, often contributing to success in intergroup competition and conflict. In turn, prosocial religious beliefs and practices spread and aggregated as these successful groups expanded, or were copied by less successful groups. This synthesis is grounded in the idea that although religious beliefs and practices originally arose as nonadaptive by-products of innate cognitive functions, particular cultural variants were then selected for their prosocial effects in a long-term, cultural evolutionary process. This framework (1) reconciles key aspects of the adaptationist and by-product approaches to the origins of religion, (2) explains a variety of empirical observations that have not received adequate attention, and (3) generates novel predictions. Converging lines of evidence drawn from diverse disciplines provide empirical support while at the same time encouraging new research directions and opening up new questions for exploration and debate. (shrink)

Cooperation towards public goods relies on credible threats of punishment to deter cheats. However, punishing is costly, so it remains unclear who incurred the costs of enforcement in our evolutionary past. Theoretical work suggests that human cooperation may be promoted if people believe in supernatural punishment for moral transgressions. This theory is supported by new work in cognitive psychology and by anecdotal ethnographic evidence, but formal quantitative tests remain to be done. Using data from 186 societies around the globe, I (...) test whether the likelihood of supernatural punishment—indexed by the importance of moralizing “high gods”—is associated with cooperation. (shrink)

The application of phylogenetic methods to cultural variation raises questions about how cultural adaption works and how it is coupled to cultural transmission. Cultural group selection is of particular interest in this context because it depends on the same kinds of mechanisms that lead to tree-like patterns of cultural variation. Here, we review ideas about cultural group selection relevant to cultural phylogenetics. We discuss why group selection among multiple equilibria is not subject to the usual criticisms directed at group selection, (...) why multiple equilibria are a common phenomena, and why selection among multiple equilibria is not likely to be an important force in genetic evolution. We also discuss three forms of group competition and the processes that cause populations to shift from one equilibrium to another and create a mutation-like process at the group level. (shrink)

In the absence of explicit punitive sanctions, why do individuals voluntarily participate in intergroup warfare when doing so incurs a mortality risk? Here we consider the motivation of individuals for participating in warfare. We hypothesize that in addition to other considerations, individuals are incentivized by the possibility of rewards. We test a prediction of this “cultural rewards war-risk hypothesis” with ethnographic literature on warfare in small-scale societies. We find that a greater number of benefits from warfare is associated with a (...) higher rate of death from conflict. This provides preliminary support for the relationship between rewards and participation in warfare. (shrink)

We propose that the crucial difference between human cognition and that of other species is the ability to participate with others in collaborative activities with shared goals and intentions: shared intentionality. Participation in such activities requires not only especially powerful forms of intention reading and cultural learning, but also a unique motivation to share psychological states with others and unique forms of cognitive representation for doing so. The result of participating in these activities is species-unique forms of cultural cognition and (...) evolution, enabling everything from the creation and use of linguistic symbols to the construction of social norms and individual beliefs to the establishment of social institutions. In support of this proposal we argue and present evidence that great apes understand the basics of intentional action, but they still do not participate in activities involving joint intentions and attention. Human children's skills of shared intentionality develop gradually during the first 14 months of life as two ontogenetic pathways intertwine: the general ape line of understanding others as animate, goal-directed, and intentional agents; and a species-unique motivation to share emotions, experience, and activities with other persons. The developmental outcome is children's ability to construct dialogic cognitive representations, which enable them to participate in earnest in the collectivity that is human cognition. Key Words: collaboration; cooperation; cultural learning; culture; evolutionary psychology; intentions; shared intentionality; social cognition; social learning; theory of mind; joint attention. (shrink)

We suggest that human culture exhibits key Darwinian evolutionary properties, and argue that the structure of a science of cultural evolution should share fundamental features with the structure of the science of biological evolution. This latter claim is tested by outlining the methods and approaches employed by the principal subdisciplines of evolutionary biology and assessing whether there is an existing or potential corresponding approach to the study of cultural evolution. Existing approaches within anthropology and archaeology demonstrate a good match with (...) the macroevolutionary methods of systematics, paleobiology, and biogeography, whereas mathematical models derived from population genetics have been successfully developed to study cultural microevolution. Much potential exists for experimental simulations and field studies of cultural microevolution, where there are opportunities to borrow further methods and hypotheses from biology. Potential also exists for the cultural equivalent of molecular genetics in “social cognitive neuroscience,” although many fundamental issues have yet to be resolved. It is argued that studying culture within a unifying evolutionary framework has the potential to integrate a number of separate disciplines within the social sciences. (shrink)

Economists and biologists have proposed a distinction between two mechanisms – “strong” and “weak” reciprocity – that may explain the evolution of human sociality. Weak reciprocity theorists emphasize the benefits of long-term cooperation and the use of low-cost strategies to deter free-riders. Strong reciprocity theorists, in contrast, claim that cooperation in social dilemma games can be sustained by costly punishment mechanisms, even in one-shot and finitely repeated games. To support this claim, they have generated a large body of evidence concerning (...) the willingness of experimental subjects to punish uncooperative free-riders at a cost to themselves. In this article, I distinguish between a “narrow” and a “wide” reading of the experimental evidence. Under the narrow reading, punishment experiments are just useful devices to measure psychological propensities in controlled laboratory conditions. Under the wide reading, they replicate a mechanism that supports cooperation also in “real-world” situations outside the laboratory. I argue that the wide interpretation must be tested using a combination of laboratory data and evidence about cooperation “in the wild.” In spite of some often-repeated claims, there is no evidence that cooperation in the small egalitarian societies studied by anthropologists is enforced by means of costly punishment. Moreover, studies by economic and social historians show that social dilemmas in the wild are typically solved by institutions that coordinate punishment, reduce its cost, and extend the horizon of cooperation. The lack of field evidence for costly punishment suggests important constraints about what forms of cooperation can or cannot be sustained by means of decentralised policing. (shrink)

In the last 60,000 years humans have expanded across the globe and now occupy a wider range than any other terrestrial species. Our ability to successfully adapt to such a diverse range of habitats is often explained in terms of our cognitive ability. Humans have relatively bigger brains and more computing power than other animals and this allows us to figure out how to live in a wide range of environments. Here we argue that humans may be smarter than other (...) creatures, but none of us is nearly smart enough to acquire all of the information necessary to survive in any single habitat. In even the simplest foraging societies, people depend on a vast array of tools, detailed bodies of local knowledge, and complex social arrangements, and often do not understand why these tools, beliefs, and behaviors are adaptive. We owe our success to our uniquely-developed ability to learn from others. This capacity enables humans to gradually accumulate information across generations, and develop well-adapted tools, beliefs, and practices that are too complex for any single individual to invent during their lifetime. (shrink)

E.O. Wilson (1975) described humans as one of the four pinnacles of social evolution. The other pinnacles are the colonial invertebrates, the social insects, and the non-human mammals. Wilson separated human sociality from that of the rest of the mammals because, with the exception of the social insect like Naked Mole Rats, only humans have generated societies of a grade of complexity that approaches that of the social insects and colonial invertebrates. In the last few millennia, human societies have even (...) begun to exceed, in numbers of individuals and degree of complexity, the societies of ants, termites, and corals. (shrink)

Acknowledgments 1. Culture Is Essential 2. Culture Exists 3. Culture Evolves 4. Culture Is an Adaptation 5. Culture Is Maladaptive 6. Culture and Genes Coevolve 7. Nothing about Culture Makes Sense except in the Light of Evolution.

Human cooperation is highly unusual. We live in large groups composed mostly of non-relatives. Evolutionists have proposed a number of explanations for this pattern, including cultural group selection and extensions of more general processes such as reciprocity, kin selection, and multi-level selection acting on genes. Evolutionary processes are consilient; they affect several different empirical domains, such as patterns of behavior and the proximal drivers of that behavior. In this target article, we sketch the evidence from five domains that bear on (...) the explanatory adequacy of cultural group selection and competing hypotheses to explain human cooperation. Does cultural transmission constitute an inheritance system that can evolve in a Darwinian fashion? Are the norms that underpin institutions among the cultural traits so transmitted? Do we observe sufficient variation at the level of groups of considerable size for group selection to be a plausible process? Do human groups compete, and do success and failure in competition depend upon cultural variation? Do we observe adaptations for cooperation in humans that most plausibly arose by cultural group selection? If the answer to one of these questions is “no,” then we must look to other hypotheses. We present evidence, including quantitative evidence, that the answer to all of the questions is “yes” and argue that we must take the cultural group selection hypothesis seriously. If culturally transmitted systems of rules (institutions) that limit individual deviance organize cooperation in human societies, then it is not clear that any extant alternative to cultural group selection can be a complete explanation. (shrink)

Cultural evolution studies are characterized by the notion that culture evolves accordingly to broadly Darwinian principles. Yet how far the analogy between cultural and genetic evolution should be pushed is open to debate. Here, we examine a recent disagreement that concerns the extent to which cultural transmission should be considered a preservative mechanism allowing selection among different variants, or a transformative process in which individuals recreate variants each time they are transmitted. The latter is associated with the notion of “cultural (...) attraction”. This issue has generated much misunderstanding and confusion. We first clarify the respective positions, noting that there is in fact no substantive incompatibility between cultural attraction and standard cultural evolution approaches, beyond a difference in focus. Whether cultural transmission should be considered a preservative or reconstructive process is ultimately an empirical question, and we examine how both preservative and reconstructive cultural transmission has been studied in recent experimental research in cultural evolution. Finally, we discuss how the relative importance of preservative and reconstructive processes may depend on the granularity of analysis and the domain being studied. (shrink)

Analyzes the nature of international disagreements and conflict resolution in terms of game theory and non-zero-sum games.

Hunter-gatherer punishment involves costs and benefits to individuals and groups, but the costs do not necessarily fit with the assumptions made in models that consider punishment to be altruistic – which brings in the free-rider problem and the problem of second-order free-riders. In this commentary, I present foragers' capital punishment patterns ethnographically, in the interest of establishing whether such punishment is likely to be costly; and I suggest that in many cases abstentions from punishment that might be taken as defections (...) by free-riders are actually caused by social-structural considerations rather than being an effect of free-rider genes. This presentation of data supplements the ethnographic analysis provided by Guala. (shrink)

Group beneficial norms are common in human societies. The persistence of such norms is consistent with evolutionary game theory, but existing models do not provide a plausible explanation for why they are common. We show that when a model of imitation used to derive replicator dynamics in isolated populations is generalized to allow for population structure, group beneficial norms can spread rapidly under plausible conditions. We also show that this mechanism allows recombination of different group beneficial norms arising in..

Human migration is nonrandom. In small scale societies of the past, and in the modern world, people tend to move to wealthier, safer, and more just societies from poorer, more violent, less just societies. If immigrants are assimilated, such nonrandom migration can increase the occurrence of culturally transmitted beliefs, values, and institutions that cause societies to be attractive to immigrants. Here we describe and analyze a simple model of this process. This model suggests that long run outcomes depend on the (...) relative strength of migration and local adaptation. When local adaption is strong enough to preserve cultural variation among groups, cultural variants that make societies attractive always predominate, but never drive alternative variants to extinction. When migration predominates, outcomes depend both on the relative attractiveness of alternative variants and on the initial sizes of societies that provide and receive immigrants. (shrink)