Polyamory and the Evolution of a Jealous God

Dawkins critiques the myth of monogamy as morality

God the voyeur wants to know what happens in your bedroom.

Image: Adam & Eve by Enrico Baj
In my earlier post, The Origins of Forbidden Love, I highlighted the absurdity of our culture (and dogmatic religions in general) in regards to sexual infidelity. Today, Richard Dawkins has an article in Newsweek that challenges this nearly ubiquitous social “crime” of infidelity. As the good doctor states:

“I want to raise another question that interests me. Why are we so obsessed with monogamous fidelity in the first place?. . . The underlying presumption -- that a human being has some kind of property rights over another human being's body -- is unspoken because it is assumed to be obvious. But with what justification?”

“Even sticking to the higher plane of love, is it so very obvious that you can't love more than one person? We seem to manage it with parental love (parents are reproached if they don't at least pretend to love all their children equally), love of books, of food, of wine (love of Chateau Margaux does not preclude love of a fine Hock, and we don't feel unfaithful to the red when we dally with the white), love of composers, poets, holiday beaches, friends . . . why is erotic love the one exception that everybody instantly acknowledges without even thinking about it? Why can a woman not love two men at the same time, in their different ways? And why should the two – or their wives -- begrudge her this?”

From the perspective of humans as primates, this view is perfectly obvious. Chimpanzees and bonobos (who share around 99% of our DNA) have what’s referred to as a multimale-multifemale mating system. Females have sex with multiple individuals in their troop and make positive choices about which males they’re most interested in. The evolution of sexual jealousy is seen in nascent form in our evolutionary cousins as a sexual partner that is observed mating with another male frequently results in the former male interrupting their l’amour. Males also compete with each other in what biologists refer to as “sperm competition.” Large amounts of ejaculate will be produced in order to “wash out” a previous males' contribution. Chimpanzee and bonobo males are extraordinarily well endowed in the testicle department as a result. A large testicle-to-body size ratio is therefore a strong predictor of a multimale-multifemale mating system.

In contrast to this, gorillas live in a single male-multifemale mating system and the large bodied males have testicles so small that anatomists have reported difficulty in even finding them. This is because there was no selection pressure from the gorilla mating system to produce a large amount of ejaculate (but this doesn’t mean that gorilla females always mate exclusively with their “harem leader,” with predictably jealous tantrums if the alpha male discovers the tryst). Gibbons are monogamous “lesser” apes and likewise have relatively small testes for their body size. In all of these cases the mating system of the primate species in question can be predicted based on male testicle size.

So this leads to the obvious question: are humans more like chimpanzees and bonobos or more like gibbons and gorillas. Unequivocally, (and as you would expect from the genetic evidence) human testicles are more like chimps and bonobos. In fact, in their analysis of the seminal protein genes SEMG1 and SEMG2 (genes that code for semen coagulation or “mating plugs” found exclusively in multimale-multifemale systems) Sarah Kingan and Steve Dorus found a direct correlation between the average number of sexual partners that females of a species will have and the selection for this gene in males. Humans lie closest to chimpanzees and bonobos at both of these loci and this strongly suggests that humans evolved with a multimale-multifemale mating system.

While sexual jealousy is a natural part of such systems, our human predilection is quite extreme and is largely enforced in a completely one-sided, patriarchal form. As I explored in my earlier post, the likely explanation is that religious dogma sought to control female sexuality as if it was the “property” of the male.

“With the power of the state to punish any violation of the law, women were relegated to the status of chattel and their sexual choices were constrained by the threat of capital punishment. It has only been with the rise of secular democracies, and the reduction of religious authority, that women have begun to reclaim their sexual freedom. The last thirty years has seen the largest rise in women’s economic and social power in human history (mostly confined to the West). It’s not coincidental that women have also seen the greatest freedom from sexual coercion and control during this same period.”

While sexual jealousy is unlikely to ever go away, we can take some comfort in the fact that our large brains allow us to recognize the absurdity of our natural reactions and to behave differently if we choose. Far from this being a call to engage in random and frivolous sex, what I (and Dawkins) are suggesting is that monogamy is not the unparalleled moral good that certain well-funded institutions have made it out to be. A committed relationship to a devoted partner is a wonderful experience and, I for one, much prefer it to a life of wanton bachelorhood. By all means be honest and true to your partner (male or female). But also be honest and true to yourself. As a society and as individuals we should understand the diversity of people’s sexual interests and talk about it openly, without clothing our language with a veneer of false piety.

References:

Kingan, S.B., Tatar, M., Rand, D.M. (2003). Reduced polymorphism in the
chimpanzee semen coagulating protein Semenogelin I. Journal of Molecular Evolution 57:159-169. doi: 10.1007/s00239-002-2463-0

Dorus, S., Evans, P.E., Wyckoff, G.J., Choi, S.S., and Lahn, B.T. (2004). Rate of molecular evolution of the seminal protein gene SEMG2 correlates with levels of female promiscuity. Nature Genetics 36: 1326-1329. doi:10.1038/ng1471