Evo psych is a largely a crock. It takes Western dynamics from the past 5k years and decides that generalizes to how humans have always lived - something that is demonstrably false. The title of this alone is just obvious bullshit. Promiscuity is a sound evolutionary impulse that serves all animals including humans - something that actual anthropologists and hard-science folks are well aware of. The fact that this was reviewed by other evo psych people doesn't impress me in the slightest. It's counterfactual to actual well established scientific principles. It's nothing more than what I said before, somebody having moral outrage and attempting to justify that.
As BBC Earth notes, “In the animal kingdom, monogamy in the strictest sense of sexual exclusivity is largely a myth. A female who mates with several different males will have more genetically diverse offspring, boosting the chances that at least some of them will thrive.”
This goes for human females as well as other non-human animals and it is confirmed in our anatomy. The coronal ridge of the human penis is specifically designed to displace semen left there by another man or men. In addition, animals that engage in mate competition prior to copulation (like gorillas) tend to have small testes and penises. Animals that instead engage in sperm competition are more well endowed relative to body size (like chimpanzees and humans) because they need to have a large supply of semen on hand to inseminate multiple partners.
Partible paternity, where several men have sex with a woman and are considered the father of her child is a long-standing practice in some parts of the world and a far from rare dynamic even today. Spreading fatherly feelings throughout the group helps to maintain solidarity and cohesion as well as promotes the well-being of a greater number of children. The children with more than one "father" are 16% more likely to make it into adulthood.
If monogamy were so "natural" why does it have to be so heavily enforced (in the places where anyone bothers to do that - which is far from all cultures even today)? Even in countries where the punishment is lashes or even death, a lot of infidelity still takes place. There's a massive amount that takes place in the West.
Pair bonding is absolutely an ancient dynamic, but it served all sorts of social functions that had nothing to do with an imagined 1950s style nuclear family - something that didn't exist for most of human history.
“Despite the belief that monogamous male-female bonding is how mothers and children were supported and thrived, the anthropologist Sarah Blaffer Hrdy and others believe it was actually female cooperative breeding, or alloparenting — ‘sharing and caring derived from the pooled energy’ of a network of ‘grandparents, aunts, uncles, siblings, distantly related kin, and non-kin’ — that shaped our evolution.” (2)
In most of rural Africa children wander in and out of the homes of unrelated adults in their villages, where they are treated as family. This stems from a more community-oriented lifestyle in general, but also from a lack of concern for parentage because sexual exclusivity is not prioritized. In fact, in some cultures, it is considered downright stingy.
As just one example (of many) the Aché of Paraguay considers a man and a woman sleeping in the same hut to be married. The marriage dissolves if one of them takes his or her hammock to another hut. “Marriages generally did not last long, and were interspersed with short romances in which one spouse might temporarily desert for a few days or weeks. Postreproductive women report a mean of thirteen spouses in a lifetime. However, marriages did tend to become more stable after two or more children were born to the couple.”
It’s completely irrelevant how much we are truly like bonobos or not — there is ample evidence in current and past human anthropology that just debunks nearly everything in that linked story to the point where it’s just kind of laughable.
