Abstract

Recent results will be presented concerning (a) the evolutionary foundations of human motivation, (b) experimental evidence concerning social preferences, and© the strategic behavior of individuals who are partly morally motivated. Since the publication of Adam Smith’s Wealth of Nations, it has been customary in economics to presume that economic agents are purely self-interested. However, research in experimental and behavioral economics suggests that human motivation is more complex, and that observed behavior is often better explained by additional motivational factors such as inequity aversion and/or a concern for others’ well-being. As a complement to that body of work, which presumes some form or other of social preferences, Ingela Alger (Toulouse School of Economics and Institute for Advanced Study in Toulouse) and I have carried out theoretical investigations into the evolutionary foundations of human motivation without any such presumption. We found that Darwinian selection, in starkly simplified but mathematically well-structured environments, favors preferences that combine self-interest with some degree of Kantian morality. Roughly speaking, individuals partly evaluate their own actions in terms of what would happen, if, hypothetically, these actions were also taken by others. Such moral motivations have important implications for economic behavior. They induce individuals to cooperate, contribute to public goods, to trust and be trustworthy, and to act in environmentally friendly ways even when their individual impact is negligible. In joint work with Ernst Fehr, Michael Kosfeld and Topi Miettinen, we compare the explanatory power of alternative models of social preferences, including morality. In a project with Ingela Alger and biologist Laurent Lehmann (Lausanne) we apply and adapt machinery from population biology in order to investigate the stochastic stability of moral behaviors.