First there was Sex at Dawn
For those unfamiliar with Sex at Dawn (Ryan and Jethá, 2010), the main thrust of the book is its claim that, contrary to conventional scientific wisdom—called the standard narrative of evolutionary psychology—pair-bonding, sexual jealousy, a male concern with paternity certainty, and host of other related traits are not natural components of evolved human sexuality. Rather, they are the product of the social arrangements attending the emergence of agriculture beginning only about 10,000 years ago. Our true nature, the authors of Sex at Dawn argue, is one closer to that of what they think bonobo sexuality is, i.e., fluid, promiscuous sexual relations between all individuals, with little sexual conflict to speak of.
Now there is Sex at Dusk by Lynn Saxon
if humans were and are naturally promiscuous, then there would not even be pair-bonding to argue for as being unnatural. Pair-bonding and marriage are cross-cultural universals, something that, as Saxon points out, Dawn does not even attempt to account for
So what is all this talk of human promiscuity in Dawn all about, really? When an argument so blatantly and so stubbornly persists in the face of what would seem to be clear, undeniable evidence against it, it is usually a good idea to look for something other than dispensation of accurate knowledge about the world as a motive. Frequently, the obverse of accurate understanding of how the world is, is ideological pronouncement on how the world ought to be.
From a review at Evolutionary Psychology (pdf)