Jonathan Grose

Recent years have witnessed an increased number of game-theoretic approaches to social norms, which apparently share some common vocabulary and methods. We describe three major approaches of this kind (due to Binmore, Bicchieri and Gintis), before comparing them systematically on five crucial themes: generality of the solution, preference transformation, punishment, epistemic conditions and type of explanation. This allows us to show that these theories are, by and large, less compatible than they seem. We then argue that those three theories struggle to account for three phenomena pertaining to social norms (namely context-dependence, conflicting norms and self-evidence), with which any complete game-theoretic account should in principle be able to deal.

The story of the fall and rise of Zahavi’s handicap principle is one of a battle between models. Early attempts at formal modeling produced negative results and, unsurprisingly, scepticism about the principle. A major change came in 1990 with Grafen’s production of coherent models of a handicap mechanism of honest signalling. This paper’s first claim is that acceptance of the principle, and its dissemination into other disciplines, has been driven principally by that, and subsequent modeling, rather than by empirical results. Secondly, there is a vast literature on biological signalling but few studies that make all of the observations necessary to diagnose the handicap mechanism. My final claim is that many of the applications of costly signalling theory in other disciplines are conceptually confused. Misinterpretations of what is meant by costly signalling are common. Demonstrating that a signal is costly is insufficient and is not always necessary in order to prove that, and explain why, a signal is honest. In addition to the biological modelling of signals, there is an economic literature on the same subject. The two run in parallel in the sense that they have had little mutual interaction. Additionally, it is the biological modelling that has been picked up, and often misapplied, by other disciplines

This paper contributes to the explanation of human cooperative behaviour, examining the implications of Brian Skyrms’ modelling of the prisoner’s dilemma (PD). Augmenting a PD with signalling strategies promotes cooperation, but a challenge that must be addressed is what prevents signals being subverted by deceptive behaviour. Empirical results suggest that emotional displays can play a signalling role and, to some extent, are secure from subversion. I examine proximate explanations and then offer an evolutionary explanation for the translucency of emotional displays. Selection acts on the basis of lifetime fitness consequences and, crucially for my argument, the intensity of selection decreases over the course of a lifetime. Hence we tend to possess traits that promote survival when young and, with regard to emotional displays, translucency allows successful maturation over our protracted period of nurturing by close kin. This is due to the vital role played by emotional interactions in the normal cognitive and social development of Homo sapiens.

Robustness analysis is widespread in science, but philosophers have struggled to justify its confirmatory power. We provide a positive account of robustness by analysing some explicit and implicit uses of within and across-model robustness in evolutionary theory. We argue that appeals to robustness are usually difficult to justify because they aim to increase the likeliness that a phenomenon obtains. However, we show that robust results are necessary for explanations of phenomena with specific properties. Across-model robustness is necessary for how-possibly explanations of multiply instantiated phenomena, while within-model robustness is necessary for explanations of phenomena with multiple evolutionary starting points. In such cases, the appeal of robustness is explanatory rather than confirmatory.

This paper contributes to the explanation of human cooperative behaviour, examining the implications of Brian Skyrms’ modelling of the prisoner’s dilemma. Augmenting a PD with signalling strategies promotes cooperation, but a challenge that must be addressed is what prevents signals being subverted by deceptive behaviour. Empirical results suggest that emotional displays can play a signalling role and, to some extent, are secure from subversion. I examine proximate explanations and then offer an evolutionary explanation for the translucency of emotional displays. Selection acts on the basis of lifetime fitness consequences and, crucially for my argument, the intensity of selection decreases over the course of a lifetime. Hence we tend to possess traits that promote survival when young and, with regard to emotional displays, translucency allows successful maturation over our protracted period of nurturing by close kin. This is due to the vital role played by emotional interactions in the normal cognitive and social development of Homo sapiens