THE GENEALOGY OF MORALS

Imagine a population of organisms with limited altruistic dispositions. For each of these organisms, there’s a variety of contexts and a range of other members of the population such that the psychological states of the focal organism – specifically the desires and the emotions – will adjust to reflect that organism’s perceptions of the wants, needs and feelings of the others. These dispositions enable the organisms to interact with one another on a number of cooperative projects, and, indeed, enable them to function as a population, to live in the same place at the same time and to encounter one another daily without too high an incidence of social friction and violence. But the dispositions are limited, cooperators are sometimes exploited, returns are uneven, and, when there is an opportunity for large selfish benefits, even longstanding allies are sometimes left in the lurch. Defections threaten to tear the social fabric, and, in their wake, much signaling is required; our organisms engage in prolonged bouts of grooming and other forms of physical reassurance.