Roissy is always worth reading, but this entry is especially worth reposting.
For the rationalist, all of Roissy's hard work can be replicated if one knows only this fact about human sexuabiology:
Women are hypergamous, that is, they seek to mate with males of high status.
Men are polygamous, that is, they seek to mate with as many women as possible.
It's all in the gametes, duh. Male sperm are more than 4.5 orders of magnitude more common than female eggs. Of course hominids would evolve to be picky about where the vastly rarer gametes get applied, and to apply the hyper-common gametes as widely as possible.