Equality in Exchange Revisited - from an Evolutionary (Genetic and Cultural) Point of View

Abstract

This paper addresses the legal relevance of recent evolutionary theoretical research on human prosociality and human strong reciprocity and the explanations it offers regarding the existence and scope of what could be called a 'sense of fairness'. To this end, I will draw on the legal example of equality in exchange in contract law on the one hand and on research on human cooperative behaviour on the other hand. I will start by making some remarks on the issue of substantive fairness in legal contract theory and in legal anthropology. I will then briefly sketch some results of some of the experiments commonly used in behavioural economics to shed light on human prosocial behaviour. Recent research not only shows that the economists' canonical assumption that individuals are entirely self-regarding is incorrect, but also indicates that there is a considerable amount of cross-cultural behavioural variability. This should set the stage for an exposition of a particular encompassing evolutionary theoretical framework underlying a particular interpretation of the experimental data. Indeed, I mainly hope to show why evolutionary analysis in law could benefit considerably from incorporating culture - and its accompanying evolutionary theory - more explicitly into its models than at present seems to be the case. I will argue that one has to be able to give a plausible evolutionary account for both the behaviour that is supposed to be regulated and the regulating behaviour itself. Moreover, rather than focusing exclusively on the - indeed likely - universal aspects of the regulated behaviour, this universality has to be connected more explicitly with the - cultural - diversity encountered in the world's legal systems. When approaching regulating behaviour in general as an evolutionary puzzling form of human large-scale cooperation, gene-culture coevolutionary theory and the related concept of cultural group selection promise to go a long way in providing this necessary connection.

Keywords: law, evolutionary analysis in law, dual inheritance theory, culture, exchange, fairness, reciprocity