In double-checking what I had stated about "kinship muting/masking" in social insects in the comments of the previous post, I stumble upon this site, Reproductive skew: An introduction to a central theory of biology. From the FAQ:

Reproductive skew theory is a mathematical approach to understanding how reproduction is partitioned among members of social groups by taking into account the ecological, social, and genetic factors within animal societies. In particular, it attempts to explain the degree to which dominant and subordinate breeders bias the total reproductive output of the group in favor of themselves. High skew groups are those in which dominant breeders obtain a large proportion of the reproduction, whereas low skew groups are those where reproduction is more evenly distributed among group members.

This is premised on animal models, though if you go further down in the FAQ the site acknowledges its debt to W.D. Hamilton, who did not shy away from implications of kin selection for human beings. The site is not complete, but the reference list has a bibliography of research in this area. Additionally, in case you didn't notice, many researchers have PDF copies of their papers on their web sites.