The Evolution of Altruism: The Sober/Wilson Model

In what follows, I critique the interpretation that Sober and Wilson offer of their group selection model in Unto Others. Sober and Wilson mistakenly claim that their model operates as an example of Simpson’s paradox and defend an interpretation of their model according to which groups are operated upon by natural selection. In the place of their interpretation, I offer one that parallels the mathematical calculation of the model’s outcome and does not depend on the postulation of a force of group selection or a value for group fitness.