By BENEDICT CAREY and TARA PARKER-POPE


The speculation over the future of the marriage of Mark Sanford, the South Carolina governor, after his affair with a woman from Argentina is likely to die off well before the family’s pain. Yet if recent research is any guide, the marriage itself has a chance to outlast all of it by many years.

Despite strong pressures against it - the liberalization of divorce laws, the vanishing stigma of divorce, continual online temptations - the marriage bond in 21st-century America is far stronger than many may assume.

Infidelity is one of the most common reasons cited by people who divorce. But surveys find most people who discover a cheating spouse stay married to that person for years afterward. Historically, the institution of marriage has not succumbed to infidelity so much as coexisted with it, as a body does with the flu virus: weakening at times, yet developing immunity from exposure.

Temptation stalks even close marriages. Psychologists at the University of Washington and the University of North Carolina reported that married people who called their relationships with their spouse “pretty happy” were twice as likely to cheat as those who called them “very happy.” But perhaps the strongest risk factor for infidelity, researchers say, lies not inside the marriage but outside: opportunity.

“People tend to assume that bad people have affairs, and good people don’t, or that affairs only happen in bad marriages,” said Peggy Vaughan, a researcher in San Diego, California, who runs the Web site dearpeggy.com. “These assumptions are just not based in reality.”

The investment in a marriage lasting more than a few years usually includes more than fidelity. Spouses share history and goals, children and strong bonds to friends and community. And there is reason to believe that such deeply integrated marriages have become more prevalent.

One of the most commonly cited statistics about marriage is that half of them end in divorce. But that number reflects the expected lifetime divorce rate of people married in the 1970s. The story is different for couples who have married more recently.

Betsey Stevenson, an assistant professor of business and public policy at the Wharton School at the University of Pennsylvania, said a study of college- educated men found that about 23 percent of those married in the 1970s had divorced by the 10th year of marriage. Among men married in the 1990s, about 16 percent had divorced by the 10th year.

The reason for the shift, some experts say, is that many couples today are delaying marriage. The data suggest that the weakest relationships, which years ago might have resulted in a marriage followed by a divorce, are now ending before the couple ever heads to the altar.

As for the Sanfords, the governor’s wife, Jenny, said earlier this summer that she had asked her husband to leave the house after discovering the affair. She also said she still believed their relationship could be repaired.


Governor Mark Sanford and his wife, Jenny, remain married, for now.