Abstract

Reciprocity is ubiquitous in our lives, both as a way of rewarding and punishing others. Consequently, the social sciences have devoted many studies to this phenomenon. However, the concept of 'reciprocity' is quite polyvalent, and is used in many different ways across different disciplines - a situation potentially prone to equivocation, which hinders fruitful interdisciplinary work. At the same time, although philosophers often invoke 'reciprocity' in their work, there is a lack of conceptual clarification about what reciprocity actually means - an eminently philosophical task. This thesis fills such a gap, by offering a general framework that allows us to understand how 'reciprocity' is used across different sciences. Such a framework consists in a grammar of several uses/meanings of reciprocity. Moreover, the thesis fills a second gap, regarding the correct interpretation of the psychological role of the reciprocity-motive in economic experiments. There has been a long-standing tradition in economics which overemphasizes the role of inequality aversion and downplays the role of reciprocity. Contrary to this deeply ingrained trend, I argue that reciprocity is the main motive of punishment of free-riders in the public goods game. My argument includes the first systematic critique of an experiment which is currently quite popular in behavioural economics. I show that the latter does not deserve the credit which it has received so far, and thus many economists need to revise their endorsement of inequality aversion. By offering a renewed interpretation of the motives in economic experiments, the thesis highlights reciprocity as a distinctive motivation. The thesis also offers tools to rethink key aspects of economic methodology, and proposes a distinction between prediction, explanation and rationalization of behaviour, in order to achieve psychologically realistic explanations of behaviour. The disciplinary home of the thesis is in philosophy of social science, economics and moral psychology.