Spitzer’s not-so-biological urge

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Psychologist David Barash’s Op-Ed article “Want a man, or a worm?” uses a veneer of outdated science to rationalize personal opinions. Using Eliot Spitzer’s sad sexual peccadilloes as a news peg, Barash makes the threadbare argument that men just can’t help themselves, titillating his readers with the tattered news that male animals copulate with more than one mate -- an example of “extra pair copulations,” or EPCs, as biologists call them.

As it happens, I just finished reading a book on EPCs and other sexual behavior in animals -- Marlene Zuk’s excellent “Sexual Selections, What We Can and Can’t Learn about Sex from Animals.” Zuk, a professor of biology at UC Riverside, takes a more logical and analytic approach than Barash, whose inspiration on male infidelity seems to have burst unedited from his reptilian brain.

It’s hardly news -- and it certainly doesn’t take an advanced degree to figure out -- that powerful people feel more entitled than average people to do all sorts of things, sexual and otherwise. It’s also been known for a very long time that EPCs are common among most animals, even birds that biologists long assumed were monogamous.


Zuk tells a very funny story about research on red-winged blackbirds and some 1950s-style assumptions about how a proper stay-at-home female red-winged blackbird would behave. As late as the 1970s, male biologists just assumed that female blackbirds would be sexually “faithful” (if you can even use such a word about birds) and that a male with lots of chicks on his territory was, by definition, a reproductive success -- a stud in the world of ornithology.

But the advent of DNA fingerprinting revealed the appalling fact that female birds regularly copulated with other males and the chicks in a male’s territory weren’t particularly likely to be his own. In short, the males were being cuckolded (and also cuckolding) on a massive scale. Decades of blackbird research was rendered meaningless almost overnight. Biologists initially reacted with actual hostility toward the female birds, as if the female birds had broken their little marriage vows, although the males were generally given a free pass for the same perfectly normal bird behavior.

What Barash leaves out of his essay is that EPCs are common among female animals as well as males. Indeed, the whole crux of the upheaval in research that Barash alludes to was the EPCs by female birds -- that fact was the big surprise to male ornithologists (the field was historically a male preserve), not the discovery of EPCs by male birds, as Barash implies. EPCs by female birds are most likely a form of genetic bet-hedging, like balancing a financial portfolio.

But the real lesson from Zuk’s book is that it’s far too easy and tempting to choose just-so stories from animals whose behavior happens to support our personal biases. Don’t do it -- for every animal that does something you approve of, there are 10 that do something you hate.

The bottom line is that other species cannot tell us what is right. It’s easy to find analogues to infidelity, rape, murder and even genocide in other species, along with a hundred other indicators of our evolutionary relatedness. But it doesn’t follow that we are automatons programmed to behave in these ways. Even a dog or a cat can choose something about how it behaves; we should expect no less of ourselves. In fact, it is precisely because we tend to do things we wish we wouldn’t that we make laws and personal resolutions. We don’t outlaw things we don’t do.

It shouldn’t be news to us that infidelity -- whether by men or women -- has roots in biology. Nor is it an inescapable consequence of celebrity and power. If voters really want a guy who stays home at night, they don’t need to elect a worm. They can choose from the large majority of American men and women who have just one partner at a time. I’d take the nice guy over the parasitic worm every time.


Jennie Dusheck is a freelance science writer who specializes in writing about biology.