Evolution, Altruism and “Internal Reward” Explanations

The debate between altruists and egoists concerns the nature of our ultimate desires. Egoists argue that all of our ultimate desires are self-directed. Altruists deny this, claiming that some of our ultimate desires are other-directed and benevolent. In Unto Others: The Evolution and Psychology of Unselfish Behavior, Elliot Sober and David Sloan Wilson examine this debate. They argue that social psychology has been unable to prove the altruist’s case because an “internal reward” explanation can always be invented to explain apparently altruistic behavior in other terms. Internal rewards are the psychological benefits one receives by performing certain other-regarding actions. Internal rewards include such benefits as the avoidance of guilt, the avoidance of painful memories, and the attainment of warm, fuzzy feelings. Despite the limitations of social psychology, Sober and Wilson believe that evolutionary theory can show that it is more likely for benevolent other-regarding motivational mechanisms to have evolved, thereby supporting the altruist’s claim. Here, I will argue for two related theses. First, if internal reward explanations pose a problem for social psychology, then they also pose a problem for evolutionary theory. Second, there is no need to think that internal reward explanations pose a problem for altruists because these explanations either do not inform us about what our ultimate motives really are or they unreasonably define out of existence the possibility of altruism. The first thesis concerns the implications of internal reward explanations for scientific attempts to tackle the egoism-altruism