SAN FRANCISCO — Men who make virginity pledges get strong social support to abstain from sex before the wedding night, but that backing disappears soon after they tie the knot, new research suggests.

These men are also taught to think of sex outside of marriage as animalistic and foul, but sacred within a marriage, according to a new study presented Aug. 17, here at the 109th American Sociological Association meeting.

As a result, male virginity pledgers can be somewhat confused and lost when it comes to sex after marriage, said study researcher Sarah Diefendorf, a sociology doctoral candidate at the University of Washington in Seattle. [The 10 Most Surprising Sex Statistics]

"They spend the first 20-something years of their lives being told that sex is wrong," Diefendorf told Live Science. "They're expected to make this transition from the beastly to the sacred, but they don't really have the tools to be able to do that effectively."

Staying pure

Overall, virginity pledges fail to keep young men and women from having sex, research has shown. But most studies of the chastity vows looked at mass-pledging events, such as the Silver Ring Thing, where throngs of teens at a concert-like venue make a vow to abstain from sex until their wedding days. Small, focused groups who make virginity pledges have a better track record of keeping that promise, Diefendorf said.

Some of purity culture's most visible aspects are aimed at women: At purity balls, girls as young as 3 years old pledge their virginity to their fathers until marriage, while abstinence-only curricula liken women who have premarital sex to chewed-up pieces of gum. But in Christian evangelical subcultures, men take virginity pledges, too, Diefendorf said. [Sex Ed, Abstinence and Contraception (Infographic)]

Strong support

To help men stick to these vows, many churches set up small groups, where men help each other as they struggle with temptations like pornography, masturbation and premarital sex.

In 2008, Diefendorf first conducted several interviews with men in one such small group, called The River, which was formed at the Message of Truth, a nondenominational mega-church in the Southwest. The group of 15 men met weekly to support each other in their struggles to remain abstinent, and many became close friends.

"They have these unbelievably honest and open conversations about sex and sexuality and various struggles with that," Diefendorf told Live Science.

The men also created an intricate system of accountability to one another, with members texting each other phrases such as "Are you behaving?" to make sure other pledgers weren't viewing porn, masturbating or engaging in illicit sexual behavior.

In the dark

But by 2011, when Diefendorf returned, 14 out of 15 of the men had married, and the church group had disbanded. Though the men remained friends, they didn't discuss sex.

"The church teaches, before marriage, keep it in the light — they want these men to be talking about these issues so that they maintain their pledges," Diefendorf said. "But post-marriage, the church teaches: keep it in the dark."

Most of the men said they viewed discussing their sex lives as inappropriate and disrespectful to their wives. But the men also felt uncomfortable talking directly to their wives about sexuality, and said they wished the church would provide more guidance after marriage, Diefendorf said. Some still struggled with a desire for extramarital sex or pornography, but didn't have an outlet to discuss it, she added.

The upshot was that, though their marriages may be happy and healthy overall, "when it comes to their sex lives, that's where they are struggling," Diefendorf said.

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