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)

This paper provides strong evidence challenging the self-interest assumption that dominates the behavioral sciences and much evolutionary thinking. The evidence indicates that many people have a tendency to voluntarily cooperate, if treated fairly, and to punish noncooperators. We call this behavioral propensity “strong reciprocity” and show empirically that it can lead to almost universal cooperation in circumstances in which purely self-interested behavior would cause a complete breakdown of cooperation. In addition, we show that people are willing to punish those who (...) behaved unfairly towards a third person or who defected in a Prisoner’s Dilemma game with a third person. This suggests that strong reciprocity is a powerful device for the enforcement of social norms involving, for example, food sharing or collective action. Strong reciprocity cannot be rationalized as an adaptive trait by the leading evolutionary theories of human cooperation (in other words, kin selection, reciprocal altruism, indirect reciprocity, and costly signaling theory). However, multilevel selection theories of cultural evolution are consistent with strong reciprocity. (shrink)

Behavioral scientists routinely publish broad claims about human psychology and behavior in the world's top journals based on samples drawn entirely from Western, Educated, Industrialized, Rich, and Democratic (WEIRD) societies. Researchers – often implicitly – assume that either there is little variation across human populations, or that these “standard subjects” are as representative of the species as any other population. Are these assumptions justified? Here, our review of the comparative database from across the behavioral sciences suggests both that there is (...) substantial variability in experimental results across populations and that WEIRD subjects are particularly unusual compared with the rest of the species – frequent outliers. The domains reviewed include visual perception, fairness, cooperation, spatial reasoning, categorization and inferential induction, moral reasoning, reasoning styles, self-concepts and related motivations, and the heritability of IQ. The findings suggest that members of WEIRD societies, including young children, are among the least representative populations one could find for generalizing about humans. Many of these findings involve domains that are associated with fundamental aspects of psychology, motivation, and behavior – hence, there are no obviousa priorigrounds for claiming that a particular behavioral phenomenon is universal based on sampling from a single subpopulation. Overall, these empirical patterns suggests that we need to be less cavalier in addressing questions ofhumannature on the basis of data drawn from this particularly thin, and rather unusual, slice of humanity. We close by proposing ways to structurally re-organize the behavioral sciences to best tackle these challenges. (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)

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.

Formal models of cultural evolution analyze how cognitive processes combine with social interaction to generate the distributions and dynamics of ‘representations.’ Recently, cognitive anthropologists have criticized such models. They make three points: mental representations are non-discrete, cultural transmission is highly inaccurate, and mental representations are not replicated, but rather are ‘reconstructed’ through an inferential process that is strongly affected by cognitive ‘attractors.’ They argue that it follows from these three claims that: 1) models that assume replication or replicators are inappropriate, (...) 2) selective cultural learning cannot account for stable traditions, and 3) selective cultural learning cannot generate cumulative adaptation. Here we use three formal models to show that even if the premises of this critique are correct, the deductions that have been drawn from them are false. In the rst model, we assume continuously varying representations under the in uence of weak selective transmission and strong attractors. We show that if the attractors are suf ciently strong relative to selective forces, the continuous representation model reduces to the standard.. (shrink)

Jesse Prinz argues that recent work in philosophy, neuroscience, and anthropology supports two radical hypotheses about the nature of morality: moral values are based on emotional responses, and these emotional responses are inculcated by culture, not hard-wired through natural selection. In the first half of the book, Jesse Prinz defends the hypothesis that morality has an emotional foundation. Evidence from brain imaging, social psychology, and psychopathology suggest that, when we judge something to be right or wrong, we are merely expressing (...) our emotions. Prinz argues that these emotions do not track objective features of reality; rather, the rightness and wrongness of an act consists in the fact that people are disposed to have certain emotions towards it. In the second half of the book, he turns to a defense of moral relativism. Moral facts depend on emotional responses, and emotional responses vary from culture to culture. Prinz surveys the anthropological record to establish moral variation, and he draws on cultural history to show how attitudes toward practices such as cannibalism and marriage change over time. He also criticizes evidence from animal behavior and child development that has been taken to support the claim that moral attitudes are hard-wired by natural selection. Prinz concludes that there is no single true morality, but he also argues that some moral values are better than others; moral progress is possible. Throughout the book, Prinz relates his views to contemporary and historical work in philosophical ethics. His views echo themes in the writings of David Hume and Friedrich Nietzsche, but Prinz supports, extends, and revises these classic theories using the resources of cutting-edge cognitive science. The Emotional Construction of Morals will stimulate and challenge anyone who is curious about the nature and origin of moral values. (shrink)

Joint activities are ubiquitous in the animal kingdom, but they differ substantially in their underlying psychological states. Humans attribute and share mental states with others in the so‐called shared intentionality. Our hypothesis is that our closest nonhuman living relatives also attribute some psychological mechanisms such as perceptions and goals to others, but, unlike humans, they are not necessarily intrinsically motivated to share those psychological states. Furthermore, it is postulated that shared intentionality is responsible for the appearance of a suite of (...) behaviors, including joint attention, declarative communication, imitative learning, and teaching, that are the basis of cultural learning and the social norms and traditions present in every human culture. (shrink)

When two or more people coordinate their actions in space and time to produce a joint outcome, they perform a joint action. The perceptual, cognitive, and motor processes that enable individuals to coordinate their actions with others have been receiving increasing attention during the last decade, complementing earlier work on shared intentionality and discourse. This chapter reviews current theoretical concepts and empirical findings in order to provide a structured overview of the state of the art in joint action research. We (...) distinguish between planned and emergent coordination. In planned coordination, agents' behavior is driven by representations that specify the desired outcomes of joint action and the agent's own part in achieving these outcomes. In emergent coordination, coordinated behavior occurs due to perception action couplings that make multiple individuals act in similar ways, independently of joint plans. We review evidence for the two types of coordination and discuss potential synergies between them. (shrink)

Empathy is thought to play a key role in motivating prosocial behavior, guiding our preferences and behavioral responses, and providing the affective and motivational base for moral development. While these abilities have traditionally been examined using behavioral methods, recent work in evolutionary biology, developmental and cognitive neuroscience has begun to shed light on the neural circuitry that instantiate them. The purpose of this article is to critically examine the current knowledge in the field of affective neuroscience and provide an integrative (...) and comprehensive view of the computational mechanisms that underlie empathy. This framework is of general interest and relevance for theory as well as for assisting future research in the domains of affective developmental neuroscience and psychopathology. (shrink)

The fact that humans cooperate with nonkin is something we take for granted, but this is an anomaly in the animal kingdom. Our species’ ability to behave prosocially may be based on human-unique psychological mechanisms. We argue here that these mechanisms include the ability to care about the welfare of others (other-regarding concerns), to “feel into” others (empathy), and to understand, adhere to, and enforce social norms (normativity). We consider how these motivational, emotional, and normative substrates of prosociality develop in (...) childhood and emerged in our evolutionary history. Moreover, we suggest that these three mechanisms all serve the critical function of aligning individuals with others: Empathy and other-regarding concerns align individuals with one another, and norms align individuals with their group. Such alignment allows us to engage in the kind of large-scale cooperation seen uniquely in humans. (shrink)

Joint action is central to countless aspects of human life. Here I examine the roots of joint action in infancy. First, I provide evidence that—contrary to popular belief—1‐year‐old infants do have the social‐cognitive prerequisites needed to participate in joint action, even in a relatively strict sense: they can read others’ goals and intentions, they have some basic understanding of common knowledge, and they have the ability and motivation to help others achieve their goals. Then I review some evidence of infants’ (...) and young children’s active participation in different types of joint action, from prelinguistic communication to more instrumental collaborations with others, with a particular focus on whether young children show evidence of an understanding of the commitments and obligations entailed in joint action. I conclude that the uniquely human ability and motivation to participate in joint action is already seen in infants by 1 year of age. (shrink)

Human cooperation is held to be an evolutionary puzzle because people voluntarily engage in costly cooperation, and costly punishment of non-cooperators, even among anonymous strangers they will never meet again. The costs of such cooperation cannot be recovered through kin-selection, reciprocal altruism, indirect reciprocity, or costly signaling. A number of recent authors label this behavior ‘strong reciprocity’, and argue that it is: (a) a newly documented aspect of human nature, (b) adaptive, and (c) evolved by group selection. We argue exactly (...) the opposite; that the phenomenon is: (a) not new, (b) maladaptive, and (c) evolved by individual selection. In our perspective, the apparent puzzle disappears to reveal a biological and evolutionary logic to human cooperation. Group selection may play a role in theory, but it is neither necessary nor sufficient to explain human cooperation. Our alternative solution is simpler, makes fewer assumptions, and is more parsimonious with the empirical data. (shrink)