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)

SummaryNeither an infant one week old nor a snail is a rational creature. If the infant survives long enough, he will probably become rational, while this is not true of the snail. If we like, we may say of the infant from the start that he is a rational creature because he will probably become rational if he survives, or because he belongs to a species with this capacity. Whichever way we talk, there remains the difference, with respect to rationality, (...) between the infant and the snail on one hand, and the normal adult person on the other; this difference is discussed here.The difference consists, it is argued, in the having of propositional attitudes such as belief, desire, intention and shame. This raises the question how to tell when a creature has propositional attitudes; snails, we may agree, do not, but how about dogs or chimpanzees? The question is not empirical; the question is what sort of empirical evidence is relevant to deciding when a creature has propositional attitudes.It is next contended that language is a necessary concomitant of any of the propositional attitudes. This idea is not new, but there seem to be few arguments in its favor in the literature; one is attempted here.Crucial to the considerations advanced is the idea that belief depends on having the concept of objective truth, and that this comes only with language.RéuméNi un bébé d'une semaine, ni un serpent ne sont des créatures rationnelles. Si le bébé survit assez longtemps, il deviendra probablement rationnel, mais ce n'est pas vrai pour le serpent. Sil'on veut, on peut dire d'emblee du bébé qu'il est une créature rationnelle parce qu'il le deviendra s'il survit ou parce qu'il appartient à une espèce qui possède cette faculté. Quoi qu'on dise, la différence subsiste, en ce qui concerné la rationalité, entre le bébé et le serpent d'une part, la per‐sonne adulte normale de lcar;autre, et c'est cette différence qui sera discutée ici.La différence consiste, selon l'auteur, en une capacityé d'avoir des attitudes propositionnelles telles que la croyance, le désir, l'intention et la honte. Ceci pose la question de savoir quand on peut dire qu'une créature a des attitudes propositionnelles; on peut se mettre d'accord sur le fait que les serpents n'en ont pas, mais qu'en est‐il des chiens et des chimpanzés? La question n'est pas empirique, elle est de savoir quelle donnée empirique va décider si oui ou non une créature a des attitudes propositionnelles.L'auteur prétend que les attitudes propositionnelles s'accompagnent nécessairement du langage. Cette idèe n'est pas nouvelle, mais il semble qu'il y a peu d'arguments qui la soutiennent dans la littérature. On en trouvera un ici, où l'on montre qu'un élément crucial de a croyance dépend de l'acquisition du concept de vérité objective, qui ne se développe qu'avec le langage.ZusammenfassungWeder ein eine Woche altes Kind noch eine Schlange sind rationale Wesen. Wenn das Kind lange genug überlebt, wird es sich wahrscheinlich zu einem vernünftigen Wesen entwickeln, wäh‐rend das für die Schlange nicht zutrifft. Wenn wir wollen, können wir vom Kind sagen, dass es von Anfang an cin rationales Wesen ist, weil es im Fallc des Ubcrlebens vernünftig werden wird oder weil es zu einer Spezies mit dieser Fähigkeit gehört. Wie auch immer wir das ausdrücken, bleibt bezüglich der Rationalität der Unterschied zwischen dem Kind und der Schlange einerseits und der erwachsenen Person andererseits zurück. Dieser Unterschied wird hier diskutiert.Es wird argumentiert, dass der Unterschied in der Fähigkeit besteht, psychologische Haltun‐gen wie Glauben, Begierden, Absichten und Scham zu haben. Damit erhebt sich die Frage, wie man entscheiden kann, wann ein Wesen solchc Einstellungcn hat; Schlangen, wird man zugeben, haben keine; wie steht es aber mit Hunden Oder Schimpansen? Die Frage ist keine empirische, sondern betrifft die Frage, welche Art von empirischen Belegen für den Entscheid relevant ist, ob ein Wesen derartige Einstellungen hat.Es wird die These aufgestellt, dass Sprachen ein notwendiger Begleitumstand einer jeglichen propositionalen Haltung ist. Der Gedanke ist zwar nicht neu, aber es finden sich wenige Argu‐mente zu seiner Stützung in der Literatur; eines wird hier ausgeführt.Entscheidend für die vorgelegten Betrachtungen ist die Auffassung, wonach Glaube vom Begriff der objektiven Wahrheit abhängt, und dieser kommt erst mit der Sprache. (shrink)

Existing accounts of shared intention (by Bratman, Searle, and others) do not claim that a single token of intention can be jointly framed and executed by multiple agents; rather, they claim that multiple agents can frame distinct, individual intentions in such a way as to qualify as jointly intending something. In this respect, the existing accounts do not show that intentions can be shared in any literal sense. This article argues that, in failing to show how intentions can be literally (...) shared, these accounts fail to resolve what seems problematic in the notion of shared intention. It then offers an account in which the problem of shared intention is resolved, because intention can indeed be literally shared. This account is derived from Margaret Gilbert’s notion of a “pool of wills,” to which it applies Searle’s definition of intention. (shrink)

Non-actual model systems discussed in scientific theories are compared to fictions in literature. This comparison may help with the understanding of similarity relations between models and real-world target systems. The ontological problems surrounding fictions in science may be particularly difficult, however. A comparison is also made to ontological problems that arise in the philosophy of mathematics.

The various behavioral disciplines model human behavior in distinct and incompatible ways. Yet, recent theoretical and empirical developments have created the conditions for rendering coherent the areas of overlap of the various behavioral disciplines. The analytical tools deployed in this task incorporate core principles from several behavioral disciplines. The proposed framework recognizes evolutionary theory, covering both genetic and cultural evolution, as the integrating principle of behavioral science. Moreover, if decision theory and game theory are broadened to encompass other-regarding preferences, they (...) become capable of modeling all aspects of decision making, including those normally considered “psychological,” “sociological,” or “anthropological.” The mind as a decision-making organ then becomes the organizing principle of psychology. (Published Online April 27 2007) Key Words: behavioral game theory; behavioral science; evolutionary theory; experimental psychology; gene-culture coevolution; rational actor model; socialization. (shrink)

A number of authors, Including Thomas Schelling and David Lewis, have envisaged a model of the generation of action in coordination problems in which salience plays a crucial role. Empirical studies suggest that human subjects are likely to try for the salient combination of actions, a tendency leading to fortunate results. Does rationality dictate that one aim at the salient combination? Some have thought so, Thus proclaiming that salience is all that is needed to resolve coordination problems for agents who (...) are rational in the sense of game theory. I argue against this position; rational agents will not necessarily aim for the salient. It remains to explain how the salient comes to be chosen by human beings. Various possibilities are noted. One involves a mechanism invoked by Hume and Wittgenstein in other contexts: we may project an unreasoned compulsion onto reason, falsely believing that rationality dictates our choice of the salient. (shrink)

Most scientific models are not physical objects, and this raises important questions. What sort of entity are models, what is truth in a model, and how do we learn about models? In this paper I argue that models share important aspects in common with literary fiction, and that therefore theories of fiction can be brought to bear on these questions. In particular, I argue that the pretence theory as developed by Walton (1990, Mimesis as make-believe: on the foundations of the (...) representational arts. Harvard University Press, Cambridge/MA) has the resources to answer these questions. I introduce this account, outline the answers that it offers, and develop a general picture of scientific modelling based on it. (shrink)

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.

This is a comment on Peter Godfrey-Smith’s, “Models and Fictions in Science”. The comments explore problems he raises if we treat model systems as fictions in a naturalized and deflationary framework.

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)

_ 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.

" Biosemantics " was the title of a paper on mental representation originally printed in The Journal of Philosophy in 1989. It contained a much abbreviated version of the work on mental representation in Language Thought and Other Biological Categories. There I had presented a naturalist theory of intentional signs generally, including linguistic representations, graphs, charts and diagrams, road sign symbols, animal communications, the "chemical signals" that regulate the function of glands, and so forth. But the term " biosemantics " (...) has usually been applied only to the theory of mental representation. Let me first characterize a more general class of theories called "teleological theories of mental content" of which biosemantics is an example. Then I will discuss the details that distinguish biosemantics from other naturalistic teleological theories. (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)

This book presents an alternative to conventional ideas about the evolution of the human intellect.

The question of whether chimpanzees, like humans, reason about unobservable mental states remains highly controversial. On one account, chimpanzees are seen as possessing a psychological system for social cognition that represents and reasons about behaviors alone. A competing account allows that the chimpanzee's social cognition system additionally construes the behaviors it represents in terms of mental states. Because the range of behaviors that each of the two systems can generate is not currently known, and because the latter system depends upon (...) the former, determining the presence of this latter system in chimpanzees is a far more difficult task than has been assumed. We call for recognition of this problem, and a shift from experimental paradigms that cannot resolve this question, to ones that might allow researchers to intelligently determine when it is necessary to postulate the presence of a system which reasons about both behavior and mental states. (shrink)

SummaryNeither an infant one week old nor a snail is a rational creature. If the infant survives long enough, he will probably become rational, while this is not true of the snail. If we like, we may say of the infant from the start that he is a rational creature because he will probably become rational if he survives, or because he belongs to a species with this capacity. Whichever way we talk, there remains the difference, with respect to rationality, (...) between the infant and the snail on one hand, and the normal adult person on the other; this difference is discussed here.The difference consists, it is argued, in the having of propositional attitudes such as belief, desire, intention and shame. This raises the question how to tell when a creature has propositional attitudes; snails, we may agree, do not, but how about dogs or chimpanzees? The question is not empirical; the question is what sort of empirical evidence is relevant to deciding when a creature has propositional attitudes.It is next contended that language is a necessary concomitant of any of the propositional attitudes. This idea is not new, but there seem to be few arguments in its favor in the literature; one is attempted here.Crucial to the considerations advanced is the idea that belief depends on having the concept of objective truth, and that this comes only with language.RéuméNi un bébé d'une semaine, ni un serpent ne sont des créatures rationnelles. Si le bébé survit assez longtemps, il deviendra probablement rationnel, mais ce n'est pas vrai pour le serpent. Sil'on veut, on peut dire d'emblee du bébé qu'il est une créature rationnelle parce qu'il le deviendra s'il survit ou parce qu'il appartient à une espèce qui possède cette faculté. Quoi qu'on dise, la différence subsiste, en ce qui concerné la rationalité, entre le bébé et le serpent d'une part, la per‐sonne adulte normale de lcar;autre, et c'est cette différence qui sera discutée ici.La différence consiste, selon l'auteur, en une capacityé d'avoir des attitudes propositionnelles telles que la croyance, le désir, l'intention et la honte. Ceci pose la question de savoir quand on peut dire qu'une créature a des attitudes propositionnelles; on peut se mettre d'accord sur le fait que les serpents n'en ont pas, mais qu'en est‐il des chiens et des chimpanzés? La question n'est pas empirique, elle est de savoir quelle donnée empirique va décider si oui ou non une créature a des attitudes propositionnelles.L'auteur prétend que les attitudes propositionnelles s'accompagnent nécessairement du langage. Cette idèe n'est pas nouvelle, mais il semble qu'il y a peu d'arguments qui la soutiennent dans la littérature. On en trouvera un ici, où l'on montre qu'un élément crucial de a croyance dépend de l'acquisition du concept de vérité objective, qui ne se développe qu'avec le langage.ZusammenfassungWeder ein eine Woche altes Kind noch eine Schlange sind rationale Wesen. Wenn das Kind lange genug überlebt, wird es sich wahrscheinlich zu einem vernünftigen Wesen entwickeln, wäh‐rend das für die Schlange nicht zutrifft. Wenn wir wollen, können wir vom Kind sagen, dass es von Anfang an cin rationales Wesen ist, weil es im Fallc des Ubcrlebens vernünftig werden wird oder weil es zu einer Spezies mit dieser Fähigkeit gehört. Wie auch immer wir das ausdrücken, bleibt bezüglich der Rationalität der Unterschied zwischen dem Kind und der Schlange einerseits und der erwachsenen Person andererseits zurück. Dieser Unterschied wird hier diskutiert.Es wird argumentiert, dass der Unterschied in der Fähigkeit besteht, psychologische Haltun‐gen wie Glauben, Begierden, Absichten und Scham zu haben. Damit erhebt sich die Frage, wie man entscheiden kann, wann ein Wesen solchc Einstellungcn hat; Schlangen, wird man zugeben, haben keine; wie steht es aber mit Hunden Oder Schimpansen? Die Frage ist keine empirische, sondern betrifft die Frage, welche Art von empirischen Belegen für den Entscheid relevant ist, ob ein Wesen derartige Einstellungen hat.Es wird die These aufgestellt, dass Sprachen ein notwendiger Begleitumstand einer jeglichen propositionalen Haltung ist. Der Gedanke ist zwar nicht neu, aber es finden sich wenige Argu‐mente zu seiner Stützung in der Literatur; eines wird hier ausgeführt.Entscheidend für die vorgelegten Betrachtungen ist die Auffassung, wonach Glaube vom Begriff der objektiven Wahrheit abhängt, und dieser kommt erst mit der Sprache. (shrink)

Preface by Daniel C. Dennett Beginning with a general theory of function applied to body organs, behaviors, customs, and both inner and outer representations, ...

David Lewis is widely credited with the first formulation of common knowledge and the first rigorous analysis of convention. However, common knowledge and convention entered mainstream game theory only when they were formulated, later and independently, by other theorists. As a result, some of the most distinctive and valuable features of Lewis' game theory have been overlooked. We re-examine this theory by reconstructing key parts in a more formal way, extending it, and showing how it differs from more recent game (...) theory. In contrast to current theories of common knowledge, Lewis' theory is based on an explicit analysis of the modes of reasoning that are accessible to rational individuals and so can be used to analyse the genesis of common knowledge. Lewis' analysis of convention emphasises the role of inductive reasoning and of salience in the maintenance of conventions over time. Footnotes Earlier versions of this paper were presented at the 13th Amsterdam Colloquium at the University of Amsterdam, at a workshop on social norms at Wissenschaftskolleg zu Berlin, and at seminars at Tilburg University and the University of Bristol. We are grateful for comments from participants at those meetings, from two anonymous referees, and from Michael Bacharach, Nick Bardsley, Cristina Bicchieri, Luc Bovens, Simon Grant, David McCarthy, Shepley Orr, Brian Skyrms, Peter Vanderschraaf, Peter Wakker and Jörgen Weibull. Robert Sugden's work was supported by the Leverhulme Trust. (shrink)

Do conventions need to be common knowledge in order to work? David Lewis builds this requirement into his definition of a convention. This paper explores the extent to which his approach finds support in the game theory literature. The knowledge formalism developed by Robert Aumann and others militates against Lewis’s approach, because it shows that it is almost impossible for something to become common knowledge in a large society. On the other hand, Ariel Rubinstein’s Email Game suggests that coordinated action (...) is no less hard for rational players without a common knowledge requirement. But an unnecessary simplifying assumption in the Email Game turns out to be doing all the work, and the current paper concludes that common knowledge is better excluded from a definition of the conventions that we use to regulate our daily lives. (shrink)

As the cognitive revolution was slow to come to the study of animal behavior, the vast majority of what we know about primate cognition has been discovered in the last 30 years. Building on the recognition that the physical and social worlds of humans and their living primate relatives pose many of the same evolutionary challenges, programs of research have established that the most basic cognitive skills and mental representations that humans use to navigate those worlds are already possessed by (...) other primates. There may be differences between humans and other primates, however, in more complex cognitive skills, such as reasoning about relations, causality, time, and other minds. Of special importance, the human primate seems to possess a species-unique set of adaptations for “cultural intelligence,” which are broad reaching in their effects on human cognition. (shrink)

Brian Skyrms offers a fascinating demonstration of how fundamental signals are to our world. He uses various scientific tools to investigate how meaning and communication develop. Signals operate in networks of senders and receivers at all levels of life, transmitting and processing information. That is how humans and animals think and interact.

It is indeed important to identify the rich variety of systems for the adaptive control of behaviour, rather than squeezing this richness into a few boxes. We need to recognise both the variety of systems for the cognitive control of adaptive behaviour and to chart the relationships between such systems. But I shall argue that these projects are not best pursued by asking about the extent of animal rationality. The argument develops in three stages. The first outlines a picture of (...) the selective regimes that drive the evolution of the sophisticated use of information by animal agents. The second argues that hominid cognition has evolved in response to a somewhat different set of " 3 " challenges and that the transmission of social information and skill has come to be both a critical and an unusual feature of hominid selective and developmental environments. The third draws upon the ideas of Dan Sperber and others in arguing that the social transmission of information introduces a vetting problem. I shall suggest that we see rationality as an evolved response to this vetting problem. (shrink)

This paper asks how, in science in general and in economics in particular, theoretical models aid the understanding of real-world phenomena. Using specific models in economics and biology as test cases, it considers three alternative answers: that models are tools for isolating the ‘capacities’ of causal factors in the real world; that modelling is ‘conceptual exploration’ which ultimately contributes to the development of genuinely explanatory theories; and that models are credible counterfactual worlds from which inductive inferences can be made. The (...) paper argues that the ‘credible worlds’ account captures significant aspects of scientific practice, even if many modellers see their work as conceptual exploration. (shrink)

In this enlightening exploration of our nearest primate relatives, Michael Tomasello and Josep Call address the current state of our knowledge about the cognitive skills of non-human primates and integrate empirical findings from the beginning of the century to the present.

In seeking to explain the evolution of social cooperation, many scholars are using increasingly complex game-theoretic models. These complexities often model readily observable features of human and animal populations. In the case of previous games analyzed in the literature, these modifications have had radical effects on the stability and efficiency properties of the models. We will analyze the effect of adding spatial structure to two communication games: the Lewis Sender-Receiver game and a modified Stag Hunt game. For the Stag Hunt, (...) we find that the results depart strikingly from previous models. In all cases, the departures increase the explanatory value of the models for social phenomena. (shrink)

Modelling became one of the primary tools of mathematical economic research in the twentieth century, but when we look at examples of how nonanalogical models were first built in economics, both the process of making representations and aspects of the representing relation remain opaque. Like early astronomers, economists have to imagine how the hidden parts of their world are arranged and to make images, that is, create models, to represent how they work. The case of the Edgeworth Box, a model (...) widely used for theoretical work in twentieth-century economics, provides a good example to explore the process of making mathematical representations of the economy. It shows how, in making these new representations, conceptual elements were developed which could not have been represented in the older verbal forms of economics. (shrink)

In their classic analyses, Hobbes and Hume argue that offensively violating a covenant is irrational because the offense ruins one’s reputation. This paper explores conditions under which reputation alone can enforce covenants. The members of a community are modeled as interacting in a Covenant Game repeated over time. Folk theorems are presented that give conditions under which the Humean strategy of performing in covenants only with those who have never offensively violated or performed with an offensive violator characterizes an equilibrium (...) of the repeated Covenant Game. These folk theorems establish that for certain ideal settings Hobbes’ and Hume’s arguments against offensively violating covenants are compelling. However, these ideal settings presuppose that the community has certain mechanisms that generate common knowledge of the identities of those with whom one should perform. I analyze the results of computer simulations of the interactions in a community whose members must rely upon private communication alone. The computer simulation data show that in this community, reputation effects cannot effectively deter members from offensively violating covenants. I conclude that Hobbes’ and Hume’s warnings against offensive violation are compelling only on condition that the community is sufficiently structured to generate common knowledge among its members. I also conclude that even in such structured communities, the Humean strategy is not the uniquely “correct” policy. (shrink)

This paper explores John Maynard Smith’s conceptual work on animal signals. Maynard Smith defined animal signals as traits that (1) change another organism’s behaviour while benefiting the sender, that (2) are evolved for this function, and that (3) have their effects through the evolved response of the receiver. Like many ethologists, Maynard Smith assumed that animal signals convey semantic information. Yet his definition of animal signals remains silent on the nature of semantic information and on the conditions determining its content. (...) I therefore compare three ways to specify the semantic content of animal signals. The first suggestion models semantic content on Maynard Smith’s theory of genetic information. On the second proposal, semantic content is equated with a condition identified by conventional content ascriptions. The third suggestion is to explain semantic content in terms of consumer-based teleosemantics. I show how these accounts equate semantic content with distinct kinds of conditions and how they differ with respect to the kinds of traits that qualify as carrying semantic information. (shrink)

Existing accounts of shared intention (by Bratman, Searle, and others) do not claim that a single token of intention can be jointly framed and executed by multiple agents; rather, they claim that multiple agents can frame distinct, individual intentions in such a way as to qualify as jointly intending something. In this respect, the existing accounts do not show that intentions can be shared in any literal sense. This article argues that, in failing to show how intentions can be literally (...) shared, these accounts fail to resolve what seems problematic in the notion of shared intention. It then offers an account in which the problem of shared intention is resolved, because intention can indeed be literally shared. This account is derived from Margaret Gilbert’s notion of a “pool of wills,” to which it applies Searle’s definition of intention. (shrink)