Genetic relatedness in chimp groups

Check out John Hawks' entry on Patrilocality and genetic relatedness in chimpanzees. They fail to support the hypothesis that interactions in large groups are driven strongly by kin selection, because the relatedness between males of the same group is only a bit higher than relatedness between groups.
In the paper, the authors assume that humans are universally patrilocal, but this still seems to be under considerable debate. (once I'm organized, I'll start giving references for this sort of thing)