Monogamy is failing men.

Not only is it failing them, but it's a "socially compelled sexual incarceration" that can lead to a life of anger and contempt, or so says Eric Anderson, an American sociologist at England's University of Winchester and author of the provocative new book, The Monogamy Gap: Men, Love, and the Reality of Cheating (Oxford University Press, $49.99).

Cheating, however, serves men pretty well. An undiscovered affair allows them to keep their relationship and emotional intimacy, and even if they're busted it's a lot easier than admitting that they wanted to screw someone else in the first place, he writes.

In his study of 120 undergraduate men, 78 percent of those who had a partner cheated, "even though they said that they loved and intended to stay with their partner." Contrary to what we may think, most men aren't cheating because they don't love their partner, he says; they cheat because they just want to have sex with others. And society shouldn't pooh-pooh that.

Monogamy's stronghold on our beliefs -- what he calls monogamism -- brings ostracism and judgment to anyone who questions or strays from its boundaries. That doesn't make sense to Anderson, who wonders why we stigmatize someone who has a fling more than couples who divorce -- throwing away a marriage rich in history and love, upsetting their kids' lives -- over something like sex.

Monogamy isn't the only "proper" way to be in a relationship, and he says it's time that society finds "multiple forms of acceptable sexual relationship types -- including sexually open relationships -- that coexist without hierarchy or hegemony." It's especially important for today's young men, for whom monogamous sex seems more boring than in generations past because of easy premarital sex and pornography.

Dr. Anderson was kind enough to answer my questions by email:

Your study includes just 120 undergraduate men, straight and gay; isn't that too small a sample to really know what's going on for men?

If I were attempting to determine what percent of men cheat, then, yes. Large-scale surveys show us that cheating remains the norm... I wanted to examine the very notion of monogamy, not morally, but rationally. I wanted to know why men want monogamy but nonetheless cheat.



You say men want to be emotionally monogamous, but their "body craves sex with other people somatically." People crave food, drugs, booze, sometimes to disastrous results. If there can be self-control with other cravings, why can't men control their body urges?

Humans are largely lousy at controlling our bodies' desires. We say we don't want to eat that Snickers bar, but we also really do want to eat it. We eat it, we feel guilty about it, and afterwards we promise ourselves not to eat one again; but we nonetheless do. It is this same phenomenon, only with cheating, that I explore.

The men in your study experienced a sharp decrease in the frequency and enjoyment of sex after two monogamous years. Since no one can sustain the kind of thrilling sex couples have in the beginning of a relationship, isn't it a healthy thing that it decreases?

I wish young men got two years of good sex before it dropped off; it's a lot less than that! It may, however, be good that the sexual desire for one's partner weans; it means that we end up staying with our long-term partners for the socioemotional connection and not for the sex. If a couple is going to raise a family, it is the emotional connection that counts, not the sexual.

Our physical desires don't die; they just change from our partner to people other than him/her. We falsely believe that when the sex dies, the relationship has also died. The reality is the opposite; when the sex dies the relationship has just begun.

What about the idea that long-term relationships make sex become deeper, more intimate and more meaningful?

The diminution of sex is simultaneous to one's emotional bonds growing stronger. Long-term partners may have more intimate sex (most just have very little) but when men see a guy or girl who turns them on, it's not intimate and meaningful sex they are craving.

Honesty is a huge part of a relationship. How good a relationship can one have when there's deception, especially since you say after men cheat spontaneously, they are more likely to plan cheating?

Honesty is good sometimes, and horrible other times. There are good reasons to lie; it is an essential skill for keeping community and relationship peace. The reason men lie about cheating is mostly because they know that if they ask for permission to have recreational sex: 1) they will be denied 2) after they are denied, they will be subject to scrutiny and increased relationship policing; 3) they will be stigmatized as immoral, and most likely broken up with. Thus, honesty doesn't meet their desires of having both a long-term partner and recreational sex with others.

The way cheating men see it, it's either cheat or don't cheat, but telling their partners they want sex outside the relationship, or telling their partners that they actually cheated, is viewed as a surefire way of achieving relationship termination. When men cheat for recreational sex -- not affairs -- they DO love their partners. If they didn't, they would break up with them.

Wouldn't it be less harmful to relationships if we became serial monogamists -- marrying two, three or four times as our sexual needs change?

Rather than marrying 20 times or more in one's life via serial monogamy, we can keep one emotional lover and just have casual, meaningless -- and hot -- sex with strangers. This gives us the long-term emotional stability we desire psychologically, alongside the hot, carnal sex we desire somatically. It makes much more sense than lying and cheating , or the difficulty of breaking up with a loved one simply because you want someone else's body for an hour.

Infidelity breaks up many marriages, but often it isn't the act of sex that's so upsetting -- it's the deception and lying, clearly problematic for the emotional intimacy you say men want. So cheating for sex may be "just about the sex" for him, but not for his partner.

Infidelity does not break marriages up; it is the unreasonable expectation that a marriage must restrict sex that breaks a marriage up. One of the reasons I wrote the book is that I've seen so many long-term relationships broken up simply because one had sex outside the relationship. But feeling victimized isn't a natural outcome of casual sex outside a relationship; it is a socialized victimhood. I'm not advocating cheating; I'm advocating open and equitable sexual relationships. When both in the couple desire this, when both realize that extradyadic sex makes their partner happy, and they therefore want their partner to have that sex, a couple will have moved a long ways toward facilitating emotional honesty, while simultaneously withering at jealousy scripts, which can be very damaging to a relationship. But if one can't achieve this with a partner that's hostile to the idea, cheating is the reasonable action.

Most of the men in your study were OK with sex on the side for them, but not their girlfriends. That seems unfair and incredibly selfish.

Monogamy is culturally compelled, so the decision has been made for us. How much of a chance would a man stand to have a second date if on the first date he said that he was interested in an open relationship? At the point men enter into relationships they, too, think they want monogamy. It's only after being in a relationship for months or years that they badly want sex with others. But by this point, they don't want to break up with their partners because they have long-standing love. Instead of chancing that love by asking for extradyadic sex, they cheat. If they don't get caught (and most don't) it's a rational choice.

But it is indeed selfish for men to want sex with others but not to want their partners to do the same. This however is not just a "man" thing. Women also cheat; they also lie about it; and they also want to be able to cheat without their partners doing the same. Monogamy is a problem for all sexes; it builds in an ownership script regardless of gender.

You say love is a "long-standing sense of security and comfort." So, wouldn't open relationships potentially pose a threat to that security since, even if couples play by their own sexual rules, there's always a chance one could end up preferring a new lover over one's partner?