Does natural selection act primarily on individual organisms, on groups, on genes, or on whole species? The question of levels of selection - on which biologists and philosophers have long disagreed - is central to evolutionary theory and to the philosophy of biology. Samir Okasha's comprehensive analysis gives a clear account of the philosophical issues at stake in the current debate.

Within paleoanthropology, the origin of behavioral modernity is a famous problem. Very large-brained hominins have lived for around half a million years, yet social lives resembling those known from the ethnographic record appeared perhaps 100,000 years ago. Why did it take 400,000 years for humans to start acting like humans? In this article, I argue that part of the solution is a transition in the economic foundations of cooperation from a relatively undemanding form, to one that imposed much more stress (...) on human motivational and cognitive mechanisms. The rich normative, ceremonial, and ideological lives of humans are a response to this economic revolution in forager lives; from one depending on immediate return mutualism to one depending on delayed and third-party reciprocation. (shrink)

The authors demonstrate that unselfish behavior is in fact an important feature of both biological and human nature. Their book provides a panoramic view of altruism throughout the animal kingdom--from self-sacrificing parasites to the human capacity for selflessness--even as it explains the evolutionary sense of such behavior.

This paper reviews and synthesizes emerging multi-disciplinary evidence toward understanding the development of social and political organization in the Last Glacial. Evidence for the prevalence and scope of political egalitarianism is reviewed and the biological, social, and environmental influences on this mode of human organization are further explored. Viewing social and political organization in the Last Glacial in a much wider, multi-disciplinary context provides the footing for coherent theory building and hypothesis testing by which to further explore human political systems. (...) We aim to overcome the claim that our ancestors’ form of social organization is untestable, as well as counter a degree of exaggeration regarding possibilities for sedentism, population densities, and hierarchical structures prior to the Holocene with crucial advances from disparate disciplines. (shrink)

In War Before Civilization, Lawrence H. Keeley argues that prehistoric as well as primitive mankind was more warlike than has been recognized by most scholars. Such scholars subscribe, according to Keeley, to “the myth of the peaceful savage,” the subtitle of his book. But Keeley, who leads a long list of Hawks, has replaced this myth with another, the “myth of the warlike savage.” Anthropologists who argue that serious warfare arose only after the rise of the state and civilization understate (...) the extent of serious warfare in prehistory. The evidence for warfare among primates, prehistoric mankind, early agriculturalists, and primitive peoples suggests that the truth lies somewhere between the myth of the peaceful savage and the myth of the warlike savage. (shrink)

Researchers from across the social sciences have found consistent deviations from the predictions of the canonical model of self-interest in hundreds of experiments from around the world. This research, however, cannot determine whether the uniformity results from universal patterns of human behavior or from the limited cultural variation available among the university students used in virtually all prior experimental work. To address this, we undertook a cross-cultural study of behavior in ultimatum, public goods, and dictator games in a range of (...) small-scale societies exhibiting a wide variety of economic and cultural conditions. We found, first, that the canonical model – based on self-interest – fails in all of the societies studied. Second, our data reveal substantially more behavioral variability across social groups than has been found in previous research. Third, group-level differences in economic organization and the structure of social interactions explain a substantial portion of the behavioral variation across societies: the higher the degree of market integration and the higher the payoffs to cooperation in everyday life, the greater the level of prosociality expressed in experimental games. Fourth, the available individual-level economic and demographic variables do not consistently explain game behavior, either within or across groups. Fifth, in many cases experimental play appears to reflect the common interactional patterns of everyday life. Key Words: altruism; cooperation; cross-cultural research; experimental economics; game theory; ultimatum game; public goods game; self-interest. (shrink)

Book Reviews Benoît Dubreuil, Economics and Philosophy, FirstView Article.

Can people be relied upon to be nice to each other? Thomas Hobbes famously did not think so, but his view that rational cooperation does not require that people be nice has never been popular. The debate has continued to simmer since Joseph Butler took up the Hobbist gauntlet in 1725. This article defends the modern version of Hobbism derived largely from game theory against a new school of Butlerians who call themselves behavioral economists. It is agreed that the experimental (...) evidence supports the claim that most people will often make small sacrifices on behalf of others and that a few will sometimes make big sacrifices, but that the larger claims made by contemporary Butlerians lack genuine support. (shrink)

Some behavioral economists argue that the honoring of social norms can be adequately modeled as the optimization of social utility functions in which the welfare of others appears as an explicit argument. This paper suggests that the large experimental claims made for social utility functions are premature at best, and that social norms are better studied as equilibrium selection devices that evolved for use in games that are seldom studied in economics laboratories.

What makes humans moral beings? This question can be understood either as a proximate question or as an ultimate question. The question is about the mental and social mechanisms that produce moral judgments and interactions, and has been investigated by psychologists and social scientists. The question is about the fitness consequences that explain why humans have morality, and has been discussed by evolutionary biologists in the context of the evolution of cooperation. Our goal here is to contribute to a fruitful (...) articulation of such proximate and ultimate explanations of human morality. We develop an approach to morality as an adaptation to an environment in which individuals were in competition to be chosen and recruited in mutually advantageous cooperative interactions. In this environment, the best strategy is to treat others with impartiality and to share the costs and benefits of cooperation equally. Those who offer less than others will be left out of cooperation; conversely, those who offer more will be exploited by their partners. In line with this mutualistic approach, the study of a range of economic games involving property rights, collective actions, mutual help and punishment shows that participants' distributions aim at sharing the costs and benefits of interactions in an impartial way. In particular, the distribution of resources is influenced by effort and talent, and the perception of each participant's rights on the resources to be distributed. (shrink)

Brian Skyrms, author of the successful Evolution of the Social Contract has written a sequel. The book is a study of ideas of cooperation and collective action. The point of departure is a prototypical story found in Rousseau's A Discourse on Inequality. Rousseau contrasts the pay-off of hunting hare where the risk of non-cooperation is small but the reward is equally small, against the pay-off of hunting the stag where maximum cooperation is required but where the reward is so much (...) greater. Thus, rational agents are pulled in one direction by considerations of risk and in another by considerations of mutual benefit. Written with Skyrms's characteristic clarity and verve, this intriguing book will be eagerly sought out by students and professionals in philosophy, political science, economics, sociology and evolutionary biology. (shrink)

Binmore argues that game theory provides a systematic tool for investigating ethical matters.

Darwin's inner voice -- Living the virtuous life -- Of altruism and free riders -- Knowing our immediate predecessors -- Resurrecting some venerable ancestors -- A natural Garden of Eden -- The positive side of social selection -- Learning morals across the generations -- Work of the moral majority -- Pleistocene ups, downs, and crashes -- Testing the selection-by-reputation hypothesis -- The evolution of morals -- Epilogue: humanity's moral future.

Ambitious and elegant, this book builds a bridge between evolutionary theory and cultural psychology. Michael Tomasello is one of the very few people to have done systematic research on the cognitive capacities of both nonhuman primates and human children. The Cultural Origins of Human Cognition identifies what the differences are, and suggests where they might have come from. -/- Tomasello argues that the roots of the human capacity for symbol-based culture, and the kind of psychological development that takes place within (...) it, are based in a cluster of uniquely human cognitive capacities that emerge early in human ontogeny. These include capacities for sharing attention with other persons; for understanding that others have intentions of their own; and for imitating, not just what someone else does, but what someone else has intended to do. In his discussions of language, symbolic representation, and cognitive development, Tomasello describes with authority and ingenuity the "ratchet effect" of these capacities working over evolutionary and historical time to create the kind of cultural artifacts and settings within which each new generation of children develops. He also proposes a novel hypothesis, based on processes of social cognition and cultural evolution, about what makes the cognitive representations of humans different from those of other primates. -/- Lucid, erudite, and passionate, The Cultural Origins of Human Cognition will be essential reading for developmental psychology, animal behavior, and cultural psychology. (from the HUP website). (shrink)

The book presents a new way of understanding Darwinism and evolution by natural selection, combining work in biology, philosophy, and other fields.

In this book, I make use of an idea from economics to suggest how noble human tendencies might not only have survived the ruthless pressures of the material world, but actually have been nurtured by them.

Ongoing advances in paleoclimatology and paleoecology are producing an ever more detailed picture of the environments in which our species evolved. This picture is important to understanding the processes by which our large brain evolved. Our large brain and its productions—toolmaking, complex social institutions, language, art, religion—are our most striking differences from our closest living relatives. Indeed, humans are unique in the animal world for our brain size relative to body mass and in the elaboration of our cultures. We are (...) also the world’s dominant organism (Vitousek et al. 1997). We achieved our present anatomy and behavioral repertoire very recently. Fossil material attributable to our species goes back perhaps 200,000 years and artifacts that strike us as representing fully modern behavioral capacities are only about 50,000 years old (Klein 1999; McBrearty and Brooks 2000), about which time anatomically modern humans spread from Africa to Eurasia (Lahr and Foley 1994). Our ecological dominance began with the evolution of agriculture starting about 10,000 years ago. Explaining the late coming of human brains is a major evolutionary puzzle. Most important animal adaptations are old. Eyes, internal skeletons, adaptations for terrestrial life and for flight all date back hundreds of millions of years. Given that big brains and culture were such an overwhelming success for us why didn’t they evolve long ago? (shrink)

Human social life is uniquely complex and diverse. Much of that complexity consists of culturally transmitted ideas and skills that underpin the operation of institutions that structure our social life. Considerable theoretical and empirical work has been devoted to the role of cultural evolutionary processes in the evolution of institutions. The most persistent controversy has been over the role of cultural group selection and gene-culture coevolution in early human populations the Pleistocene. We argue that cultural group selection and related cultural (...) evolutionary processes had an important role in shaping the innate components of our social psychology. By the Upper Paleolithic humans seem to have lived in societies structured by institutions, as do modern populations living in simple societies. The most ambitious attempts to test these ideas have been the use of experimental games in field settings to document human similarities and differences on theoretically interesting dimensions. These studies have documented a huge range of behavior cross-culturally, although no societies so far examined follow the expectations of selfish rationality. These data are at least consistent with operation of cultural group selection and gene-culture coevolution operating in the deep tribal past and with the contemporary importance of cultural evolution in the evolution of institutions and institutional diversity. (shrink)

Robert Boyd*†, Herbert Gintis‡, Samuel Bowles§, and Peter J. Richerson¶.