Alejandro Rosas

Sober and Wilson have recently claimed that evolutionary theory can do what neither philosophy nor experimental psychology have been able to, namely, "break the deadlock" in the egoism vs. altruism debate with an argument based on the reliability of altruistic motivation. I analyze both their reliability argument and the experimental evidence of social psychology in favor of altruism in terms of the folk-psychological "laws" and inference patterns underlying them, and conclude that they both rely on the same patterns. I expose the confusions that have led Sober and Wilson to defend a reliability argument while rejecting the experimental evidence of social psychology.

Altruism is a central concept in evolutionary biology. Evolutionary biologists still disagree about its meaning (E.O. Wilson 2005; Fletcher et al. 2006; D.S. Wilson 2008; Foster et al. 2006a, b; West et al. 2007a, 2008). Semantic disagreement appears to be quite robust and not easily overcome by attempts at clarification, suggesting that substantive conceptual issues lurk in the background. Briefly, group selection theorists define altruism as any trait that makes altruists losers to selfish traits within groups, and makes groups of altruists fitter than groups of non-altruists. Inclusive fitness theorists reject a definition based on within- and between-group fitness. Traits are altruistic only if they cause a direct and absolute fitness loss to the donor. The latter definition is more restrictive and rejects as cases of altruism behaviors that are accepted by the former. Fletcher and Doebeli (2009) recently proposed a simple, direct and individually based fitness approach, which they claim returns to first principles: carriers of the genotype of interest “must, on average, end up with more net direct fitness benefits than average population members.” This seductively simple proposal uses the concept of assortment to explain how diverse kinds of altruists end up on average with more net fitness than their non-altruistic rivals. In this paper I shall argue that their approach implies a new concept of altruism that contrasts with and improves on the concept of the inclusive fitness approach

Recent developments in evolutionary game theory argue the superiority of punishment over reciprocity as accounts of large-scale human cooperation. I introduce a distinction between a behavioral and a psychological perspective on reciprocity and punishment to question this view. I examine a narrow and a wide version of a psychological mechanism for reciprocity and conclude that a narrow version is clearly distinguishable from punishment, but inadequate for humans; whereas a wide version is applicable to humans but indistinguishable from punishment. The mechanism for reciprocity in humans emerges as a meta-norm that governs both retaliation and punishment. I make predictions open to empirical investigation to confirm or disconfirm this view.