Curing Casanova
July 18, 2004
by Walter Kirn, New York Times

One of the least persuasive doctrines of the religion I belonged to as a teenager held that temptation was a gift from God because doing right would have no meaning if people lacked the freedom to do wrong. The idea, as I understood it at the time, was that even though it would be a sin to pick up a pretty girl at the church dance and drive her to the dark abandoned chicken farm known as ''the coop'' where we Mormon kids held our makeout sessions, I should nevertheless feel grateful for the fact that I desperately desired to do so. Except I didn't feel grateful; I felt confused. That good actions often felt deeply frustrating and bad actions supremely pleasurable seemed to me to be creation's greatest flaw, not its crowning virtue.

My old confusion came back to me when I read a recent series of articles in the science journal Nature concerning the genetic and chemical roots of sexual behavior in the vole. The study in question involved the prairie vole, a rodent species whose males are naturally monogamous and enjoy spending time with their partners, and the meadow vole, whose males prefer to mate with many females and then like to wander off and be alone. What could account for this difference, the scientists wondered, between the two groups of closely related creatures? And could the naughty, randy voles be civilized?

Yes, it turned out, they could be. It wasn't hard, in fact. To make the meadow voles act like prairie voles when it came to so-called pair bond formation, the researchers merely injected a gene harvested from the ideal-husband voles into the forebrains of the rock-star voles. (The forebrain is the seat of passion? Who knew?) The resulting behavioral modifications were quantified by recording the amount of time the meadow-vole couples spent ''in side-by-side contact ('huddling').'' The voles in the control group spent as much time ''huddling'' with strangers as they did with their initial mates, while the voles who had received the shot were far more loyal -- a change of affairs that the scientists attributed to the increased number of receptors for vasopressin, a neurotransmitter, caused by the new gene.

Though it's dangerous to personify the meadow vole (or to meadow-vole-ify human beings), it's hard to ignore the experiments' implications, social, medical, moral and theological, for our own species. By modifying the brain through simple genetic therapy -- or, better, a pill -- could Casanova-ism be cured, the incidence of male adultery reduced and thousands of troubled marriages repaired? And assuming that such feats were possible, would they be wished for?

Unlike depression or bipolar disorder, a tendency toward promiscuity isn't necessarily painful to the men (or women) who harbor it. Indeed, if they can find ways to indulge such a predisposition without causing too much romantic collateral damage, it may even be a solace of sorts. What immediate advantage -- besides a clearer conscience, perhaps, or a more tranquil domestic situation -- would a medical fix offer, particularly once you understand that what was at one time considered a moral weakness is really a matter of vasopressin receptors? Don Juans have been waiting for most of human history for such an excuse. If it comes, I bet they'll take it.

How would this alter our concept of sexual sin, though? The problem with a drug that makes us be good (not just feel good, like more traditional drugs) is that being good, when it comes naturally, isn't that big an achievement, morally speaking. That's how my old Mormon bishop would see it, at least. For him, what made a deed a moral deed was its superhuman difficulty. Not only wouldn't he be impressed by a man who didn't commit adultery because his brain chemistry basically wouldn't let him, he would no doubt sense that should this treatment catch on, he'd be out of a job. He wouldn't like this development any more than old-school Freudian analysts like Prozac.

The fact that those most in need of a monogamy injection would also be the least inclined to have one, and that the clergy who might be able to force them to might feel fundamentally threatened by its existence, doesn't mean, of course, that such medicine wouldn't be convenient in countless ways. After all, if women can make men wear sensation-dulling condoms, they can make them take the meadow-vole treatment, too, even if it never arrives in pill form and requires the insertion of a needle in the forebrain. Of course, some women might break ranks and forsake imposing the therapy in order to indulge their bad-boy boyfriends. But I'd be willing to wager that the majority could lock down the opposite sex within a month or two by agreeing among themselves to make the therapy a precondition for intercourse.

Then again, the study was done on voles. I don't know that I've ever seen a vole, but if they're like moles, only smaller, with pointier noses (which for some reason is how I picture them), I doubt that they're subject to the inner agonies that human males feel regarding sex and love. Most of us -- me, for example -- are good boys, basically, who occasionally ''huddle around'' and then feel awful about it. Or maybe we never stray, yet we still feel awful because we wish we had. Human beings are a self-conscious mess. Even if our sexual inclinations could be realigned through genetic tinkering, we'd still be free to decline the treatment, counteract it with another procedure or regret it once we'd had it. The voles didn't know what was being done to change them, and they had no choice about whether to let it happen. One day, the temptation to stray just vanished as if by divine intervention. But we'll have to freely decide whether to circumscribe our own forbidden desires -- a mental trap no rodent needs to fear.