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One very difficult issue here is how we know whether people actually are in monogamous marriages, even when they think they are, and how we measure happiness, and whether we are comparing frisky apples to horny oranges. Dan Savage joins the debate:

A lot of those blissfully happy people in monogamous long-term relationshipsand it seems odd to credit monogamy for their happiness instead of the personality traits and interpersonal skills that allowed them to form those long-lasting partner bondsactually aren't in monogamous relationships. People cheat and they don't always inform their partners and spouses; and just as premarital sex isn't a modern phenomenon, cheatingand getting away with itisn't exactly a new thang.

Perhaps some studies have found a high correlation between monogamy and happiness. But have those studies compared people in successful, long-term non-monogamous relationships with people in successful, long-term non-monogamous relationships? I suspect not.

I'd wager that most-if-not-all of these studies have compared people in long-term monogamous relationshipsor people in what they believe to be monogamous relationshipsto people who aspired to be in stable monogamous relationships and failed, e.g. people who have gone from one failed monogamous startup relationship to the next. These studies would have very little tell us very little about how honest, ethical non-monogamy stacks up against traditionally monogamous relationship models.

Maybe we need to check out a serious study used in these arguments and see what it actually contains and how it avoids these obvious and inherent flaws. When we've actually investigated monogamy in the animal kingdom, we've discovered that monogamy is close to non-existent. Almost no mammals mate for life; one of mankind's closest genetic cousins, the bonobos, jerk each other off as a way of saying hi. Even the reputedly monogamous world of birds - remember Nora Ephron's words "Want monogamy? Marry a swan!"? - what we thought we knew, we found out to be false:

Even swans aren't monogamous. But the myth of monogamy didn't disappear overnight. The tell-tale hiss of its deflation began several decades ago. One now-famous study, for example, sought to assess vasectomy as a possible means of population control among red-winged blackbirds. To their surprise, the researchers Yi-Yuanji-Two-gibbons-in-an-oak-tree discovered that female blackbirds, mated to vasectomized males, were nonetheless laying eggs that hatched! Evidently, there was some hanky-panky going on in the blackbird world.

And not just blackbirds. By the 1980's, studies employing blood typing as well as analyses of proteins were leading researchers to question whether social monogamy and sexual monogamy were necessarily synonymous. Then came DNA fingerprinting in the 1990's, and a veritable avalanche of new findings. Time and again, it was revealed that 10, 20, even sometimes 40 percent of nestlings were not fathered by the social father. The apparent mother, on the other hand, usually is what she seems to be, reinforcing the adage "Mommy's babies, Daddy's maybes."

Reports of extra-pair copulations -- henceforth, E.P.C.'s -- in animals previously thought to be monogamous have come hot and heavy during the last decade. Increasingly, biology journals have featured articles with titles such as "Behavioral, Demographic, and Environmental Correlates of Extra-Pair Fertilizations in Eastern Bluebirds," "Extra-Pair Copulations in the Mating System of the White Ibis," "Extra-Pair Paternity in the Shag, as Determined by DNA Fingerprinting," "Genetic Evidence for Multiple Parentage in Eastern Kingbirds," "Extra-Pair Paternity in the Black-Capped Chickadee," "Density-Dependent Extra-Pair Copulations in the Swallow," and "Patterns of Extra-Pair Fertilizations in Bobolinks." We've even seen these oxymoronic reports: "Promiscuity in Monogamous Colonial Birds" and "Extra-Pair Paternity in Monogamous Tree Swallows."

The situation has reached a point whereby a failure to find E.P.C.'s in ostensibly monogamous species -- that is, cases in which monogamous species really turn out to be monogamous -- is itself reportable, leading to the occasional appearance of such reassuring accounts as "DNA Fingerprinting Reveals a Low Incidence of Extra-Pair Fertilizations in the Lesser Kestrel" or "Genetic Evidence for Monogamy in the Cooperatively Breeding Red-Cockaded Woodpecker."

Nor have mammals been exempt. Gibbons, for example, were long thought to be lifetime monogamists. No longer. Ditto for essentially every species that has been investigated with any thoroughness.

One wonders what a similarly rigorous study would find in the human species. But such a study would take a police state to undertake. Until then, we may have to treat much of the factual discussion as provisional. What appears to be the case, to anyone with open eyes, is that humankind is mildly monogamous and more than mildly hypocritical about it all. Which seems a sane adaptation to reality. If we start from that premise, then we can allow for a variety of ways to handle it.

(Photos: a flock of red-winged blackbirds via Wiki; Painting of gibbons by Yi Yuanji (ca 1000-ca 1064).

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