Yesterday, I covered some of the more compelling arguments that have convinced me that humans aren’t “built” for long term sexual monogamy. I also hinted at why I believe monogamy has taken over modern culture — the acquisition of wealth. But there are still a lot of glaring questions, and I’d like to at least touch on a few of them while outlining the case for why monogamy is so prevalent despite being “unnatural.”
To begin with, let me offer a caveat. Whatever else we might be, we humans are very flexible in our mating. Even today, we see everything from communal mate swapping to highly stratified polygamy to near monogamy. And if there is still a question of whether we are most naturally drawn to monogamous long term pair bonds or not, it’s clear that we are capable of long term monogamy. But it is a very difficult strategy to follow, and seems counter-intuitive on several levels.
Monopoly vs. Diversification
I think long term monogamy is best described as an extremely conservative sexual strategy. If you think about it, there’s only one strategy that’s more conservative — celibacy. Let’s look at it in terms of genes, and compare it with non-monogamy.
- In strict monogamy, when a man has chosen his mate, he has cut off all other avenues of reproduction, and limited the number of children he can have, probably to three or four. If his wife has inferior genes, or is infertile, he has effectively ended his gene line.
- In strict monogamy, when a woman chooses a mate, she has effectively bet her entire genetic legacy on one roll of the dice. If the man has inferior genes, or is infertile, she has effectively ended her gene line.
- In non-monogamy, a man “rolls the dice” with multiple women, increasing the number of children he can have, and reducing the effect of any infertility or inferior genes in any particular partner.
- In non-monogamy, a woman increases the genetic diversity of her offspring by having children by several men. This reduces the effect of any infertility or inferior genes in any particular partner.
Let’s stop here for a moment. At this level, it seems that non-monogamy is the best strategy for reproducing. It’s not so unlike investing in the stock market. Any investment banker will tell you diversity is the key to ensuring growth for the long term. So why don’t we follow the same kind of sexual strategy?
Sure, we can postulate that the A-list genes suffer in this scenario. It would be better if the top female and male reproduced exclusively with each other, right?
Not necessarily. The strength of evolution is diversity. Environments are dynamic, and what’s good for this generation may not be good for the next generation. The species which survive the best are those which are genetically diverse enough that “potential” advantageous genes are well distributed in the population. So it’s nice that Blade Killemdead has blond hair, a killer smile, and a broad chest. But who knows what sort of pathogen resistance might be hiding out in Joe Average. And your children might be the ones who need that resistance when the plague hits next year. If you have one child with Blade, and one with Joe, there’s a better chance that one of them survives, since you’re prepared for war and plague. With two children by either Joe or Blade, there’s a better chance that both of them will die.
So I don’t know if I’m buying the “superior gene” line of thinking that seems so prevalent these days. I think it’s mostly social. Bill Gates’ genes may not be any better than Joe Plumber’s, but the social rewards and personal windfall from mating with Bill are far superior. And that brings me around to the crux of the issue. Monogamy doesn’t appear to be about genetics or “natural sexual tendencies.” It’s about social and material acquisition.
When we start thinking about it this way, the “big picture” becomes quite clear. Males possess most of the wealth in the world. And let’s not sugar coat this. Even in very egalitarian cultures, exclusive legal monogamy is one of the fastest and easiest ways to wealth for many women. Genetically, it doesn’t make sense for a woman to monopolize one man. Financially, it makes all the sense in the world.
But there’s still a nagging question. If monogamy is all about women, why has it always been the men pushing so hard for it? A thorough answer to this question is well beyond the scope of a blog entry, but I’d like to offer a compelling thought. When monogamy became all the rage, women were the property of men. It was all about protecting personal property. It was NOT about sexual exclusivity. A brief scan of the history of infidelity laws bears this out. Until quite recently, the majority of them were framed as one man committing a crime against another by usurping his property, or in the case of a woman stepping out, the property itself committing a crime against its owner!
Monogamy is, and has always been about ownership. The framework has shifted substantially since women gained legal equality with men, and now women are as capable as men of exploiting it for their own personal gain. But it’s still about property acquisition. Not sexual exclusivity.
Have you ever thought about bastards? Why have we despised them so much throughout history? If you think for a moment, you’ll realize that it’s the threat they pose to the family fortune. It’s not that they’re a crime against nature. They’re a crime against wealth acquisition. Bastard children have often been disowned or exiled by their families. The puzzling thing is that many were raised by other families and had perfectly fine lives. Even though they were not raised by their biological families. Isn’t that a puzzle? It should be if we’re selling the story that the almighty “parental resource unit” makes us monogamous.
And while we’re on puzzles: How do you feel about your brother or sister having sex with your exclusive sexual partner? If it really is all about passing on genes, you should feel better about that than your partner having sex with a total stranger, right? At least if a sibling is involved in the mating, a significant portion of your genes will be in the child.
Sperm competition can be either external or internal. Males can fight it out with their claws or fists or teeth, and the winner gets to have sex, OR all the males can have a go, and their sperm can duke it out in the female’s reproductive tract.
As far as the math goes, it really doesn’t matter very much. One male still passes on his genes, and the rest don’t. Think about that for a moment. If you’ve got “superior fighting sperm,” and you and all your frat buddies have sex with Suzy Sorority during the annual Drunken Barn Dance, you’re still going to come out on top in the genetic race. In a very real way, it’s also better for Suzy, since she’s bypassing all the fake Rolex’s, and Daddy’s money, and all the other things that are so socially appealing, and going straight for the real money — the best genes. (And let’s be honest… isn’t it appealing to you on some level, whether you’re male or female, to dispense with all the fightin’ and feudin’ and get to have sex with all the boys or girls you find hot?)
There are lots of indications that human females are built for just this kind of scenario — although probably toned down a little bit. The human vagina is a minefield for sperm. It’s designed to kill weak sperm and prevent them from even getting near the precious egg. Sperm themselves are designed for fighting, and for blocking access to invader sperm.
Of course, it doesn’t have to be either external or internal. There can certainly be pre-selection AND internal sperm competition. And by all accounts, that’s what humans have always done, regardless of our social mating system. In very ancient cultures, it was only the members of one tribe that participated in the orgy. Or maybe it was only the men who had been victorious in the last hunt. Or all the youth who were ready to become men. Whatever. But external selection has always been coupled with internal selection.
The question, then, is why it has gotten so bottlenecked today, and why the pre-selection process has been refined to the point that internal sperm competition is usually avoided completely. We still have to return to our original “liberal” strategy of diversification. Genetically, it is still beneficial to everyone if each individual has sex with lots of people. For the less desirable males, it means they get at least a shot at reproduction, and if their bad looks are just a fluke, and they have hearty sperm, both they and their offspring win. For the females, the same logic applies.
In general, we can say that too much external filtering ought to be bad for the gene pool as a whole. There will be more losers, since each monogamous couple with one infertile partner will cost one fertile genetic legacy. With diversification, every fertile female will reproduce.
So in the end, I have to return to my original idea: Monogamy is not about sexual strategy. It’s about wealth. Pure and simple.