05/31/2013 10:17 pm ET Updated Jul 31, 2013

The Morality of Infidelity

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Earlier this week, the Huffington Post reviewed the remarkable findings of a Gallup poll that sought to find exactly where the needle sits in the moral compass of Americans. The poll asked people about the moral acceptability of 20 hot-button issues, ranging from gay relationships, to out-of-wedlock marriages, to abortion, to doctor assisted suicide.

The findings varied from issue to issue. For instance, more than 90 percent of those surveyed did not see have any moral problems with using birth control, and more than two-thirds thought divorce was morally okay. So, which of the 20 issues generated the lowest approval rating? Infidelity. Only 6 percent of people felt that "married men and women having affairs" fell within the bounds of moral decency.

Pundits scurried to make sense of what this statistic teaches us about our culture. One of the most vexing questions is why should divorce (deemed acceptable to 68 percent of people) be so much less morally wrong than affairs, especially when you consider the distressing emotional and financial effects of ending a marriage? In contrast, affairs need not wreck a marriage -- they can remain hidden much of the time, and can sometimes happen without anyone getting hurt. No harm, no foul -- so what's all the moral fuss about?

It boils down to one simple principle. Infidelity consists of lying and cheating, and few people in society find that morally acceptable. Moreover, we're not talking about stealing paperclips from the office or fudging on tax returns; these transgressions are made against a partner to whom you have sworn absolute loyalty. Note that the survey didn't ask about murder (although it asked about the death penalty -- approved by 62 percent) and it didn't ask about rape (although it asked about pornography -- acceptable to 31 percent of respondents). But if it had asked about stealing, murder, or rape, what percentage of people would have given those things the moral green light? There's a short list of morally wrong things that virtually everyone holds reprehensible, and on that handful of items nearly everyone includes lying.

Unwed pregnancy (67 percent acceptability) and even stem cell research (59 percent acceptability) are choices made by individuals about the direction they themselves wish to go. On the other hand, infidelity is not a victimless act. The decision to have an affair involves a secret choice made by one person to rob another person of what is rightfully his or hers: fidelity. It is an act that includes lying, family neglect and often the theft of time and money.

Does that sound harsh? It ought to. Sociology experts and evolutionary psychologists can argue all day long as to whether monogamy is "natural," or whether it is reasonable for anyone to keep unrealistic vows made in earnest. And while the data on the prevalence of infidelity is daunting -- about 40 percent of couples will be affected by an affair -- the majority of married people have never had affairs. It's amazing all the "unnatural" things humans can do when they put their minds to it!

So if you're surprised at the moral outrage against infidelity, you shouldn't be. Plain and simple, it's wrong.