This article examines two questions about scientists’ search for knowledge. First, which search strategies generate discoveries effectively? Second, is it advantageous to diversify search strategies? We argue pace Weisberg and Muldoon, “Epistemic Landscapes and the Division of Cognitive Labor”, that, on the first question, a search strategy that deliberately seeks novel research approaches need not be optimal. On the second question, we argue they have not shown epistemic reasons exist for the division of cognitive labor, identifying the errors that led (...) to their conclusions. Furthermore, we generalize the epistemic landscape model, showing that one should be skeptical about the benefits of social learning in epistemically complex environments. (shrink)

Amodel for inventing newsignals is introduced in the context of sender–receiver games with reinforcement learning. If the invention parameter is set to zero, it reduces to basic Roth–Erev learning applied to acts rather than strategies, as in Argiento et al. (Stoch. Process. Appl. 119:373–390, 2009). If every act is uniformly reinforced in every state it reduces to the Chinese Restaurant Process—also known as the Hoppe–Pólya urn—applied to each act. The dynamics can move players from one signaling game to another during (...) the learning process. Invention helps agents avoid pooling and partial pooling equilibria. (shrink)

Strong reciprocators possess two behavioural dispositions: they are willing to bestow benefits on those who have bestowed benefits, and they are willing to punish those who fail to bestow benefits according to some social norm. There is no doubt that peoples' behaviour, in many cases, agrees with what we would expect if people are strong reciprocators, and Fehr and Henrich argue that many people are, in fact, strong reciprocators. They also suggest that strongly reciprocal behaviour may be brought about by (...) specialised cognitive architecture produced by evolution. I argue that specialised cognitive architecture can play a role in the production of strongly reciprocal behaviour only in a very attenuated sense, and that the evolutionary foundations of strong reciprocity are more likely cultural than biological. (shrink)

Traditional contractarian theories based upon the theory of rational choice suffer from a number of well-known problems. For example, in positing the initial choice problem, the outcome selected by rational agents depends upon the specification of the choice situation, the range of alternatives the agents may choose from, and the nature of the rational agents themselves. Modifying any one of these three parameters likely alters the choice outcome, creating difficulties for social contract theorists who attempt to base a theory of (...) normativity upon such a choice. I describe a new form of contractarian theories, which I call evolutionary contractarianism. Although evolutionary contractarianism still seeks to ground a theory of normativity in the individual choices of rational agents, it recognizes both that agents are, at best, only boundedly rational, and that the dynamics of interaction between rational agents cannot be ignored. I explicitly concentrate on developing an evolutionary contractarian theory for norms of fair division in two bargaining games, laying a general framework which may in principle be extended to norms of fair division in other contexts. (shrink)

This symposium discusses J.-L. Dessalles's account of the evolution of language, which was presented in Why we Talk (OUP 2007).

It is certainly the case that morality governs the interactions that take place between individuals. But what if morality exists because of these interactions? This book, first published in 2007, argues for the claim that much of the behaviour we view as 'moral' exists because acting in that way benefits each of us to the greatest extent possible, given the socially structured nature of society. Drawing upon aspects of evolutionary game theory, the theory of bounded rationality, and computational models of (...) social networks, it shows both how moral behaviour can emerge in socially structured environments, and how it can persist even when it is not typically viewed as 'rational' from a traditional economic perspective. This book also provides a theory of how moral principles and the moral sentiments play an indispensable role in effective choice, acting as 'fast and frugal heuristics' in social decision contexts. (shrink)

Whereas The Stag Hunt and the Evolution of Social Structure supplements Evolution of the Social Contract by examining some of the earlier work’s strategic problems in a local interaction setting, no equivalent supplement exists for The Dynamics of Rational Deliberation . In this article, I develop a general framework for modeling the dynamics of rational deliberation in a local interaction setting. In doing so, I show that when local interactions are permitted, three interesting phenomena occur: (a) the attracting deliberative equilibria (...) may fail to agree with any of the Nash equilibria of the underlying game, (b) deliberative dynamics which converged to the same deliberative outcome in The Dynamics of Rational Deliberation may lead to different deliberative outcomes here, and (c) Bayesian deliberation seems to be more likely to avoid nonstandard deliberative outcomes, contrary to the result reported in The Dynamics of Rational Deliberation , which argued in favour of the Brown–von Neumann–Nash dynamics. (shrink)

This chapter contains section titled: Kin Selection Reciprocity Group Selection Coercion Mutualism Byproduct Mutualism Local Interactions References.

Always connect—that is the imperative of today’s media. But what about those moments when media cease to function properly, when messages go beyond the sender and receiver to become excluded from the world of communication itself—those messages that state: “There will be no more messages”? In this book, Alexander R. Galloway, Eugene Thacker, and McKenzie Wark turn our usual understanding of media and mediation on its head by arguing that these moments reveal the ways the impossibility of communication (...) is integral to communication itself—instances they call excommunication. In three linked essays, _Excommunication_ pursues this elusive topic by looking at mediation in the face of banishment, exclusion, and heresy, and by contemplating the possibilities of communication with the great beyond. First, Galloway proposes an original theory of mediation based on classical literature and philosophy, using Hermes, Iris, and the Furies to map out three of the most prevalent modes of mediation today—mediation as exchange, as illumination, and as network. Then, Thacker goes boldly beyond Galloway’s classification scheme by examining the concept of excommunication through the secret link between the modern horror genre and medieval mysticism. Charting a trajectory of examples from H. P. Lovecraft to Meister Eckhart, Thacker explores those instances when one communicates or connects with the inaccessible, dubbing such modes of mediation “haunted” or “weird” to underscore their inaccessibility. Finally, Wark evokes the poetics of the infuriated swarm as a queer politics of heresy that deviates from both media theory and the traditional left. He posits a critical theory that celebrates heresy and that is distinct from those that now venerate Saint Paul. Reexamining commonplace definitions of media, mediation, and communication, _Excommunication_ offers a glimpse into the realm of the nonhuman to find a theory of mediation adequate to our present condition. (shrink)

Multiarm bandit problems have been used to model the selection of competing scientific theories by boundedly rational agents. In this paper, I define a variable-arm bandit problem, which allows the set of scientific theories to vary over time. I show that Roth-Erev reinforcement learning, which solves multiarm bandit problems in the limit, cannot solve this problem in a reasonable time. However, social learning via preferential attachment combined with individual reinforcement learning which discounts the past, does.

Sender–receiver games, first introduced by David Lewis ([1969]), have received increased attention in recent years as a formal model for the emergence of communication. Skyrms ([2010]) showed that simple models of reinforcement learning often succeed in forming efficient, albeit not necessarily minimal, signalling systems for a large family of games. Later, Alexander et al. ([2012]) showed that reinforcement learning, combined with forgetting, frequently produced both efficient and minimal signalling systems. In this article, I define a ‘dynamic’ sender–receiver game in (...) which the state–action pairs are not held constant over time and show that neither of these two models of learning learn to signal in this environment. However, a model of reinforcement learning with discounting of the past does learn to signal; it also gives rise to the phenomenon of linguistic drift. 1 Introduction2 Dynamic Signalling Games with Reinforcement Learning2.1 Introducing new states2.2 Swapping state–action pairs3 Discounting the Past3.1 Learning to signal in a dynamic world3.2 An unexpected outcome: linguistic drift4 ConclusionAppendix: A Markov Chain Analysis. (shrink)

Evolutionary game theoretic accounts of justice attempt to explain our willingness to follow certain principles of justice by appealing to robustness properties possessed by those principles. Skyrms (1996) offers one sketch of how such an account might go for divide-the-dollar, the simplest version of the Nash bargaining game, using the replicator dynamics of Taylor and Jonker (1978). In a recent article, D'Arms et al. (1998) criticize his account and describe a model which, they allege, undermines his theory. I sketch a (...) theory of evolutionary explanations of justice which avoids their methodological criticisms, and develop a spatial model of divide-the-dollar with more robust convergence properties than the models of Skyrms (1996) and D'Arms et al. (1998). (shrink)

We introduce a dynamic model for evolutionary games played on a network where strategy changes are correlated according to degree of influence between players. Unlike the notion of stochastic stability, which assumes mutations are stochastically independent and identically distributed, our framework allows for the possibility that agents correlate their strategies with the strategies of those they trust, or those who have influence over them. We show that the dynamical properties of evolutionary games, where such influence neighborhoods appear, differ dramatically from (...) those where all mutations are stochastically independent, and establish some elementary convergence results relevant for the evolution of social institutions. (shrink)

Decision theory faces a number of problematic gambles which challenge it to say what value an ideal rational agent should assign to the gamble, and why. Yet little attention has been devoted to the question of what an ideal rational agent is, and in what sense decision theory may be said to apply to one. I show that, given one arguably natural set of constraints on the preferences of an idealized rational agent, such an agent is forced to be indifferent (...) among entire families of goods, and hence cannot choose among them. This result illustrates the dangers of speaking of the choices of an ?ideal rational agent? when one does not make precise the exact nature of the idealizing assumptions. The result may also be viewed as providing an upper bound on the kinds of idealizing assumptions which can be made for rational agents, beyond which the very concept of choice becomes attenuated. (shrink)

The Pasadena game is an example of a decision problem which lacks an expected value, as traditionally conceived. Easwaran (2008) has shown that, if we distinguish between two different kinds of expectations, which he calls ‘strong’ and ‘weak’, the Pasadena game lacks a strong expectation but has a weak expectation. Furthermore, he argues that we should use the weak expectation as providing a measure of the value of an individual play of the Pasadena game. By considering a modified version of (...) the Pasadena game, I argue that weak expectations may provide a very poor measure of the value of an individual play of the game, and hence should not be used to value individual plays unless further information is taken into consideration. (shrink)

Recent years have seen increased interest in the question of whether it is possible to provide an evolutionary game-theoretic explanation for certain kinds of social norms. I sketch a proof of a general representation theorem for a large class of evolutionary game-theoretic models played on a social network, in hope that this will contribute to a greater understanding of the long-term evolutionary dynamics of such models, and hence the evolution of social norms.

In the course of history, many individuals have the dubious honor of being remembered primarily for an eponym of which they would disapprove. How many are aware that Joseph-Ignace Guillotin actually opposed the death penalty? Another notable case is that of Maria Agnesi, an Italian woman of privileged, but not noble, birth who excelled at mathematics and philosophy during the eighteenth century. In her treatise of 1748, Instituzioni Analitiche, she provided a comprehensive summary of the current state of knowledge concerning (...) both integral calculus and differential equations. Later in life she was elected to the Bologna Academy of Sciences and, in 1762, was consulted by the University of Turin for an opinion on the work of an up-and-coming mathematician named Joseph-Louis Lagrange. (shrink)

“Parting is such sweet sorrow.” Taste metaphors provide a rich vocabulary for describing emotional experience, potentially serving as an adaptive mechanism for conveying abstract emotional concepts using concrete verbal references to our shared experience. We theorized that the popularity of these expressions results from the close association with hedonic valence shared by these two domains of experience. To explore the possibility that this affective quality underlies the semantic similarity of these domains, we used a behavioral “odd-one-out” task in an online (...) sample of 1059 participants in order to examine the semantic similarity of concepts related to emotion, taste, and color, another rich source of sensory metaphors. We found that the semantic similarity of emotion and taste concepts was greater than that of emotion and color concepts. Importantly, the similarity of taste and emotion concepts was strongly related to their similarity in hedonic valence, a relationship which was also significantly greater than that present between color and emotion. These results suggest that the common core of valence between taste and emotion concepts allows us to bridge the conceptual divide between our shared sensory environment and our internal emotional experience. (shrink)

At the very end of the 19th century, Gabriele Tarde wrote that all society was a product of imitation and innovation. This view regarding the development of society has, to a large extent, fallen out of favour, and especially so in those areas where the rational actor model looms large. I argue that this is unfortunate, as models of imitative learning, in some cases, agree better with what people actually do than more sophisticated models of learning. In this paper, I (...) contrast the behaviour of imitative learning with two more sophisticated learning rules (one based on Bayesian updating, the other based on the Nash-Brown-von Neumann dynamics) in the context of social deliberation problems. I show for two social deliberation problems, the Centipede game and a simple Lewis sender-receiver game, that imitative learning provides better agreement with what people actually do, thus partially vindicating Tarde. (shrink)

Cheap talk has often been thought incapable of supporting the emergence of cooperation because costless signals, easily faked, are unlikely to be reliable (Zahavi and Zahavi, 1997). I show how, in a social network model of cheap talk with reinforcement learning, cheap talk does enable the emergence of cooperation, provided that individuals also temporally discount the past. This establishes one mechanism that suffices for moving a population of initially uncooperative individuals to a state of mutually beneficial cooperation even in the (...) absence of formal institutions. (shrink)

Rachlin's idea that altruism, like self-control, is a valuable, temporally extended pattern of behavior, suggests one way of addressing common problems in developing a rational choice explanation of individual altruistic behavior. However, the form of Rachlin's explicitly behaviorist account of altruistic acts suffers from two faults, one of which questions the feasibility of his particular behaviorist analysis.

Strong reciprocators possess two behavioural dispositions: they are willing to bestow bene ts on those who have bestowed bene ts, and they are willing to punish those who fail to bestow bene ts according to some social norm. There is no doubt that peoples' behaviour, in many cases, agrees with what we would expect if people are strong reciprocators, and Fehr and Henrich argue that many people are, in fact, strong reciprocators. They also suggest that strongly reciprocal behaviour may be (...) brought about by specialised cognitive architecture produced by evolution. I argue that specialised cognitive architecture can play a role in the production of strongly reciprocal behaviour only in a very attenuated sense, and that the evolutionary foundations of strong reciprocity are more likely cultural than biological. (shrink)

In a highly influential work, List and Pettit (Group Agency: The Possibility, Design, and Status of Corporate Agents, Oxford University Press, 2011) draw upon the theory of judgement aggregation to offer an argument for the existence of nonreductive group agents; they also suggest that nonreductive group agency is a widespread phenomenon. In this paper, we argue for the following two claims. First, that the axioms they consider cannot naturally be interpreted as either descriptive characterisations or normative constraints upon group judgements, (...) in general. This makes it unclear how the List and Pettit argument is to apply to real world group behaviour. Second, by examining empirical data about how group judgements are made by a powerful international regulatory board, we show how each of the List and Pettit axioms can be violated in ways which are straightforwardly explicable at the level of the individual. This suggests that group agency may best be understood as a pluralistic phenomenon, where close inspection of the dynamics of intragroup deliberation can reveal that what prima facie appears to be a nonreductive group agent is, in fact, reducible. (shrink)

One common interpretation of the Hobbesian state of nature views itas a social dilemma, a natural extension of the well-knownprisoner''s dilemma to a group context. Kavka (1986)challenges this interpretation, suggesting that the appropriate wayto view the state of nature is as a quasi social dilemma. Iargue that Hobbes''s remarks on the rationality of keeping covenantsin the state of nature indicate that the quasi social dilemma doesnot accurately represent the state of nature. One possiblesolution, I suggest, views the state of nature (...) as a social dilemmabetween groups rather than individuals. Although thiscleanly represents the strategic problem faced in the state ofnature, it also means we should take intergroup dynamics intoaccount when putting forth a solution. I argue that Hobbes''ssolution of commonwealth by institution – the favored solution forHobbesian social contract theories – will not work in the state ofnature viewed this way. (shrink)

A hallmark of intelligent behavior is rationality – the disposition and ability to think analytically to make decisions that maximize expected utility or follow the laws of probability. However, the question remains as to whether rationality and intelligence are empirically distinct, as does the question of what cognitive mechanisms underlie individual differences in rationality. In a sample of 331 participants, we assessed the relationship between rationality and intelligence. There was a common ability underpinning performance on some, but not all, rationality (...) tests. Latent factors representing rationality and general intelligence were strongly correlated (r =.54), but their correlation fell well short of unity. Rationality correlated significantly with fluid intelligence (r =.56), working memory capacity (r =.44), and attention control (r =.49). Attention control fully accounted for the relationship between working memory capacity and rationality, and partially accounted for the relationship between fluid intelligence and rationality. We conclude by speculating about factors rationality tests may tap that other cognitive ability tests miss, and outline directions for further research. (shrink)

The replicator dynamics have been used to study the evolution of a population of rational agents playing the Nash bargaining game, where an individual's "fitness" is determined by an individual's success in playing the game. In these models, a population whose initial conditions was randomly chosen from the space of population proportions converges to a state of fair division approximately 62% of the time. (Higher rates of convergence to final states of fair division can be obtained by introducing artificial correlations (...) into the models.) Spatial models of the Nash bargaining game exhibit considerably more robust convergence properties. These properties are considered at length, and a sufficient condition for convergence to fair division is proved. (shrink)