In response to the question in the title, Does Altruism Exist?, David Sloan Wilson argues forcefully that altruism exists and that the biological mechanism of group selection is responsible. He argues that group selection should be taken especially seriously for humans, since cultural evolution is especially important for us. Economists' view of basic human motivations should then include altruism. Wilson promotes a strong form of pervasive altruism, which seems bound to be inconsistent with many economic phenomena. Although a moderate version of the position he advocates is not easily dismissed, it is unclear what such an extended theory would look like.

This paper first considers the implications of biological evolution for economic preferences. It analyzes why utility functions evolved, considers evidence that utility is both hedonic and adaptive, and suggests why such adaptation might have evolved. Time preference and attitudes to risk are treated—in particular, whether the former is exponential and the latter are selfish. Arguments for another form of interdependence—a concern with status—are treated. The paper then considers the evolution of rationality. One hypothesis examined is that human intelligence and longevity were forged by hunter-gatherer economies; another is that intelligence was spurred by competitive social interactions.