Here's an interesting theory about why humans moved from promiscuity to pairing/monogamy, but I can't help but think that it leaves out one large and glaringly obvious factor:
A new study from Sergey Gavrilets, professor of ecology, biology, and mathematics at the University of Tennessee-Knoxville, reviews the current evidence and offers an intriguing hypothesis. The transition from “promiscuity to pair-bonding,” Gavrilets writes in the journal PNAS, occurred only when lesser male hominids, realizing their physical inferiority, adopted a “provider” role in partnerships, and female hominids, in turn, began to show fidelity to these partners. (Others have postulated that the rise of agriculture helped smooth the way for the transition.) The role of female choice is not often considered in evolutionary biology, but if Gavrilets’ models are correct, it may be integral to explaining our past.
The factor I'm thinking of is not mentioned in the article or in the linked to abstract. It could be discussed in the paper itself, but that's behind a paywall and I'm not that interested. The factor I'm talking about is probably as obvious to you as it is to me and that is venereal disease, or STIs as the preferred acronym now. How can you theorize about the origin of promiscuity vs. pairing/monogamy in human history and not take incurable sexually transmitted disease into account?
I don't know exactly how far back the documentation of human STIs goes, certainly as far as the Old Testament and ancient Greek and Roman writings. I'm sure they were around much further back in history than that. And though ignorance and superstition would confuse things quite a bit, even primitive societies would eventually recognize the main method of transmission through repeated examples of cause and effect.
Keep in mind also that up until a very short time ago in the timeline of human history, STIs were often the gift that kept on giving, sometimes right up to a painful and nasty death. Some scholars believe that what was commonly called leprosy in ancient writings also included some cases of syphilis and perhaps other diseases. Given their potentially devastating effects and the lack of real treatment for such diseases, it is no surprise that virginity before marriage and monogamy after would become societal and religious standards. I think that many religious rules against certain foods also arose because of a similar recognition of cause and effect combined with a poor understanding of what was really taking place and an inability to treat the resulting illness.
I can't say that professor Gavrilets is wrong in his study, but I would like to see how even a primitive understanding of STIs would affect his computer models.