The morning after François Mitterrand's funeral, a photo showed the late president's mistress and illegitimate daughter standing by his grave alongside his wife and sons. That tableau has become famous internationally as proof that the French are uniquely tolerant of extramarital affairs.

In fact, although French presidents seem to have an infidelity record approaching 100 per cent, ordinary Frenchmen claim to be quite faithful. In a 2004 national survey, just 3.8 per cent of married men and 2 per cent of women said they had had more than one sex partner in the past year (the best approximation of infidelity) -- fewer than in similar surveys in the U.S. and the U.K.

If France isn't the world capital of adultery, which country is? I set off around the world to find out.

I quickly discovered that global sex research is patchy and incomplete. Even serious researchers can't even agree on what to call infidelity. Nigerians prefer the term "sexual networking." The Finns use the morally neutral term "parallel relationships." A French team uses an expression perhaps better suited for an accounting course: “simultaneous multi-partnerships.”

Then there’s the tricky matter of what constitutes cheating. A poll in one South African magazine had separate categories for men who cheat, and men who cheat “while drunk.” One American survey defined sex as "either vaginal or anal intercourse," while another decided that sex is a "mutually voluntary activity with another person that involves genital contact and sexual excitement or arousal, that is, feeling really turned on, even if intercourse or orgasm did not occur." Americans haven’t yet tried to count their so-called “emotional affairs,” in which the “cheaters” might never meet.

Many countries simply have no reliable sex statistics. National surveys are expensive, and many governments are either too prudish or too poor to help pay for them (private funding is seldom sufficient). America’s first representative national survey only got off the ground in the 1990s, after conservative members of Congress spent years trying to block it. Hints of Japan’s infidelity levels come only from the enormous size of the country’s paid-sex industry, which is famously frequented by married businessmen. A legal loophole permits a man and a woman to strike a private agreement for sex. Understandably, the state would rather not be confronted with the details.

In Russia, just talking about sex research can be hazardous. Soviet governments barely permitted any public discussion of sex, let alone a survey that might embarrass the government by showing that Russians were engaging in banned activities like extramarital affairs. And though the Soviet Union collapsed in 1991, Russia’s Orthodox church keeps the current government from funding practically anything related to sex.

“There were never and will not be in the foreseeable future national surveys,” said Igor Kon, a septuagenarian who’s Russia’s most prominent sexologist. When I visited him in Moscow, Kon showed me the pamphlet in which a group of Russian academics denounced him as a “danger to the Russian society and state” because of his calls for basic sex education and research. Earlier, hoodlums had attacked him while he delivered a lecture at Moscow University, and vandals defaced the door to his apartment. Kon was bothered least when he got a phone call threatening to bomb his apartment, since if the caller was serious Kon would already be dead. “To kill someone in Moscow is not a big problem,” he explained.

Despite the lack of hard data, in Russia and elsewhere there are facts on the ground. In Moscow, women in their forties told me that, by necessity, they only date married men. That’s because, since the life expectancy for Russian men has fallen so sharply (to 59) that by age 65 there are just 46 men left for every 100 women.

And it was clear that Russian men flaunted this demographic advantage. With the exception of a pastor (who was sitting with his wife at the time), I didn’t meet a single married man in Russia who admitted to being monogamous. A family psychologist whom I had intended to interview as an “expert” boasted about her own extramarital relationships and insisted that given Russia’s endemic alcoholism, violent crime, and tiny apartments, affairs are “obligatory.”

Muslim countries tend to be even stricter about sex research. It’s impossible to know how much cheating goes on in places like Iran, where convicted adulterers can be stoned to death. But again there are facts -- or at least impressions -- on the ground. In Indonesia, the most populous Muslim country, the middle-class women and men I met said that adultery is absolutely wrong because the Koran forbids it. Then they revealed that many of their married friends, and sometimes they themselves, had lovers. In these circles, the attitude toward affairs seemed almost casual: local slang for a no-strings romp was "afternoon nap," and a brief love affair was a "wonderful interval."

I didn’t find evidence anywhere in the world that religious people are particularly faithful. Within the social circles I studied in Indonesia, the fact that polygamy is legal seemed to legitimize the idea that a man won’t be satisfied with just one woman. "Polygamy is something that induces adultery, because before they get married for the second time there's a period of adultery, " said sociologist Paulus Wirutomo of the University of Indonesia. "Islam is not permissive, but there's an emphasis on formality. "

I did find that, all over, money shapes the rules of infidelity. Men in rich countries are generally much more faithful than their counterparts in poor ones. That’s in part because first-world cheaters tend to be punished more severely. In America, a single affair can mean losing your marriage, your assets, your status and your self respect. Just 3.9 percent of married American men said they’d had more than one partner in the last year, according to the 2004 General Social Survey carried out by the National Opinion Research Center. Even in wealthy countries where the taboo on cheating is weaker than in the U.S. -- Australia, Switzerland and Italy, for instance -- husbands claim to be quite faithful too.

Among women, it’s just the opposite. Women in poor countries say they cheat infrequently, perhaps because they have less financial and social clout than their husbands. But in wealthier countries, where the status of men and women is more equal, levels of male and female infidelity -- while still quite low -- are fairly equal too.

While it’s impossible to get an exact measure of infidelity, there are some clues about where the most cheating goes on. Beginning in the 1990s, researchers tracking the spread of HIV began extensively mapping sexual behavior in sub-Saharan Africa. Their findings were astonishing: in the tiny West African nation of Togo, with a population of less than six million, 37 percent of married or cohabiting men said they’ve had more than one sex partner in the last year (the figure includes polygamists). Trailing just behind the Togolese were men in Cameroon, the Ivory Coast, Mozambique and Tanzania. In South Africa, even the AIDS educator at a Cape Town metal company told me that of course he had a girlfriend as well as a wife.

And so the dubious title of world infidelity capital goes to a region: sub-Saharan Africa. And with ordinary citizens cheating at such astonishing levels, one can only imagine what African politicians are up to. Surely they put even French presidents to shame.

Author's Bio: 

Pamela Druckerman is the author of Lust in Translation: Infidelity from Tokyo to Tennessee.