Pulled this paragraph out because I don't think it is supported by the concensus of scientific literature. If you can source this as an accepted, published theory, please be bold and add it back. I've done a significant edit to this article based on my memory of a Scientific American article. This article would be much stronger with sourcing of the theories . Rossami 22:01, 2 Jul 2004 (UTC)

But if the female does manage to sneak off and copulate with another male, she can get meat from that other male for herself and her offspring -- giving her an incentive to "cheat". So the same pair bonding that cements a male to "his" female also leads, inevitably, to jealousy, fratricide between males, and even male violence toward his mate, to "keep her in line".

And I cut these paragraphs because they didn't seem to flow well but I couldn't figure out where to put them that would be any better. They're a bit of a tangent. Rossami 22:01, 2 Jul 2004 (UTC)

Female humans may not be able to consciously articulate why some males seem more masculine than others, but unconscious parts of their minds, adapted by evolution, can spot those signs.
And once again, concealed fertility aids the female -- since the male can never be sure when the female conceives, he can never be sure that a particular child is his; he must take his chances and support all "his" mate's offspring on the hope they are his.

In this here article a man explain how this is an in reliable source. Which is true because a women doesn't have to have sex with only her partner to get off, but she can go sneak around with the next male and then shes feeling another way towards him because the other male cant do it for her.

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