Altruism, benevolence and culture

Human cultural groups appear well designed, but is this apparent design due to altruism or due to self-sewing behaviours? Sober and Wilson argue that human cultures are founded on group-selected altruism. This argument assume s that individually selected self-sewing traits are not being misidentified as altruistic. A simple definition of individual selection suggests that S ober and Wilson fail to separate one such trait, called benevolence, from a ltruism. Benevolent individuals act selfishly but provide an incidental ben efit to their neighbours. The female-biased Hamiltonian sex ratios are used to illustrate benevolence, and a financial analogy is used to emphasize wh y such traits are individually advantageous. Benevolence can only evolve in a spatially structured population, illustrating the importance of separati ng individual selection in structured and unstructured populations. Unlike benevolence, altruism can only evolve by group selection and, as a result, is vulnerable to selfish 'cheats' that exploit the self-sacrifice of altrui sts.