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“What’s the matter with Jewish men today?” Josh Greenman, the opinion editor of the New York Daily News, raised that question after Anthony Weiner’s latest sexting relapse. Jodi Kantor, a Slate alumna and New York Times correspondent, responded with a 1,200-word essay on the troubles of Weiner, Eliot Spitzer, and San Diego Mayor Bob Filner. Although the three cases are very different, these “libidinous, self-sabotaging politicians are causing grimaces among fellow Jews,” Kantor noted. They’re discrediting the assumption “that Jewish men make solid husbands.”

Where did we get the idea that Jews are faithful in marriage? Sounds to me like an old yente’s tale. The data don’t support it. Jews stray as much as—if not more than—spouses of other faiths.

The best evidence for Jewish fidelity comes from a 2005 survey commissioned by Durex, the contraceptive company. The survey included more than 300,000 people in 41 countries. On a list of possible “sexual experiences you’ve had,” the questionnaire asked respondents whether they’d ever had an “extramarital affair.” Israel came in dead last. Across the 41 countries, the average percentage of respondents who said they’d had an affair was 22. In Israel, it was 7.

I’m skeptical of this survey for several reasons. In addition to the usual mystery—how many people had affairs but said they didn’t?—Durex didn’t publish the full methodology. So we don’t know how representative the samples were, nor do we know the exact wording of the question. What we do know is that the countries included in the survey had a Western tilt. Twenty-four were European. Four others were Anglo: Australia, Canada, New Zealand, and the United States. Only three—Indonesia, Malaysia, and Turkey—were majority Muslim.

What happens when we include some of the missing countries? Two researchers at the City University of New York answered that question last year in the American Sociological Review. Using eight years of data from the U.S. Agency for International Development’s Demographic and Health Survey, they examined rates of self-reported extramarital sex in 31 countries. Most were developing nations. Six were majority Muslim. Five others were 20 to 40 percent Muslim. More than 300,000 respondents—married people who had engaged in sex in the past 12 months—were included in the sample. They were asked whether their most recent partner was their spouse. If the answer was no, this was counted as extramarital sex.

Fewer than 1 percent of Muslims, Hindus, and Buddhists indicated that they had strayed. Among Christians, the figure was 3 percent. Among Jews, it was 4 percent. Were Muslims just less likely to acknowledge an affair? Apparently not—indices of deception were lower for Muslims than for other groups. The principal factors in Muslim communities, the authors theorized, were cultural discouragement of adultery and limited opportunities due to sexual segregation.

What about American Jews? Again, there’s no evidence of greater fidelity. In 2006, researchers at the University of Texas published an analysis of data from the National Opinion Research Center’s General Social Survey. Using the survey’s direct question—“Have you ever had sex with someone other than your husband or wife while you were married?”—they examined four years of responses, breaking them down by the faith in which each respondent was raised. Among people with no religious background, the infidelity rate was 21 to 22 percent. Among Protestants, it was 18 percent. Among Jews and Catholics, it was 16 to 17 percent. Among people raised in other faiths—a residual category “comprised largely of people indicating Christian, Orthodox, and [Muslim]” backgrounds—the rate was 13 percent. This pattern roughly matched the 2012 survey of developing nations, though the authors of the U.S. study concluded that “religious affiliation is not a significant predictor of extramarital sex.”

Beyond these reports, there isn’t much. The authors of the 2006 paper found only one prior study, published in 1975, that examined the relationship between infidelity and the respondent’s religious denomination. In that case, the final analysis concluded that religion and other demographic factors “did not emerge as the important variables.” A massive survey of American women in their 20s and 30s, conducted around the same time by Redbook, reported a higher overall adultery rate, perhaps due to self-selection bias. But the comparative results resembled the 2006 study: Jews and Catholics tied, with Protestants slightly more likely to report cheating.

Do Jewish men make good husbands? Many of them do. So do many Hindus, Buddhists, and Mormons. If Anthony Weiner’s wife, Huma Abedin, had chosen to play the probabilities, the safer bet might have been a fellow Muslim. But playing the probabilities is never as smart as learning more about the man or woman you’re dealing with. And that’s not just a good rule for marriage. It’s a good rule for life.

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