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.