Group selection in humans?

In reference to my previous post about multi-level selection, I have an admission to make, I am generally more open to group selection, strictly speaking interdemic selection, for human beings than I am for other creatures. The reasoning is culture, as my intuition is that ingroup vs. outgroup psychological dynamics can generate the relatively high ratio of intergroup vs. intragroup variance that is needed for this form of selection to keep up with within group selection (e.g., individual selection). To some extent, I have been influenced by the book, Not by Genes Alone, a popularization of the work of theoretical anthropologists Robert Boyd and Peter J. Richerson. Additionally, recently I have been in a discussion with Judith Rich Harris about the role that multi-level selection plays in No Two Alike. But finally, I am going to publish a 10 questions with James F. Crow on my other weblog tomorrow morning, and in it I ask him about group selection and he responded that he did believe that it was important for human evolution. I suspected as much as I did a literature review before asking him the questions. But in any case, reputation matters, if the most eminent population geneticist alive believes in its relevance for human evolution, I am more hesitant to dismiss it. More later....