This is the second part on the evolution of human mating behavior, comparing evidence for promiscuity and pair-bonding in our species. Please see the Introduction here.
“I’ll be frank. True monogamy is rare. So rare that it is one of the most deviant behaviors in biology.” (Olivia Judson 2002: 153)
In their best-selling book, Sex at Dawn, Chris Ryan and Cacilda Jethá suggest that there is a good amount of direct and circumstantial evidence that extended monogamy does not come easily for humans, and that this derives at least in part from our fairly promiscuous evolutionary history. (To clarify, they use the term ‘promiscuous’ not in a judgmental way, but merely to convey having multiple sex partners). Their main premise is that rigid monogamy became common only after our ancestors made the shift from hunting and gathering to agriculture. With agriculture came an emphasis on fixed settlements, private property that could be inherited, genetic paternity, and female sexual fidelity. They argue that this stands in contrast to our hunting-gathering past, when sexual relationships were more open and not confined to an exclusive pair-bond.