WHY CHEAT?

WASHINGTON -- It's about a missing person, but it's about sex, too.

And until police find Chandra Levy, part of the focus will stay on the sex life of Rep. Gary Condit, who had an affair with the 24-year-old former intern before she vanished May 1.

It's become yet another tale about the liaisons of a powerful Washington politician, and one that raises age-old questions about why married people cheat.

Two other women, a United Airlines flight attendant and a former Condit staffer, have said they, too, had affairs with the California Democrat, who is 53 and has been married 34 years.

Male adulterers step out on their wives for many reasons, sex counselors and family therapists say: They enjoy seducing women, think each conquest affirms their masculinity, believe they're entitled to unlimited sex or are trying to boost their egos and repair low self-esteem.

Adultery often is not caused by a problem in the marriage.

"The majority of these people, and mostly they're men, would say that they're committed to their marriage and their families and that this is just casual sex," said Shirley Glass, a Baltimore psychologist who studies infidelity.

Often, she said, the stereotype is true -- men want youth and beauty, while women in these relationships seek power or perhaps someone who can lavish them with expensive gifts.

"So the politician and the young, aspiring single woman (each) captures that prototype," Glass said.

Adultery, by its nature, can't be accurately measured. But over the years, researchers have concluded that married men are up to twice as likely as women to commit it.

A 1998 study of American sexual behavior by the University of Chicago found 21.5 percent of husbands owning up to adultery, compared with 12.5 percent of wives.

Extramarital relationships aren't about love, says Frank Pittman, a psychiatrist and family therapist in Atlanta and the author of "Private Lies: Infidelity and Betrayal of Intimacy."

They are "motivated by narcissism, by insecurity, by competitiveness with the other guys, by a fear of intimacy," he said. Fearful of exposing personal flaws, some men will get involved with a succession of women rather than get too close to just one, he said.

Some therapists even believe philandering can be passed down -- like father, like son.

"Infidelity is a legacy carried down through the generations in families such as the Kennedys, where the men are committed to family life but have affairs, and the women 'stand by their men."' Glass said.

And some men behave as though they're still going through puberty.

"It's like what the man has learned as a young adult is this idea that a real man never says 'No' to a sexual opportunity," said Barry McCarthy of Washington, a clinical psychologist, sex therapist and co-author of "Couple Sexual Awareness," who teaches at American University.

Even so, men aren't the only ones at fault, said Diane Sollee of Washington, founder and director of the Coalition for Marriage, Family and Couples Education, which provides family counseling.

"What are we to make of these immoral women who know that (Condit's) married, know that he's got children?" she asked.

Condit, the teetotaling son of a Baptist preacher, cultivated a squeaky-clean image during almost three decades in politics.

Two recent polls found people in his Modesto, Calif.-based district less inclined to vote for him as a result of his relationship with Levy.

"He shouldn't be in office, but nobody's perfect," said Will Barnett, 47, of Modesto, who votes Democratic. "Look at Bill Clinton, but he was still a good president."

Terry Boyd, 60, a Modesto contractor and Republican, said he'd vote for Condit "unless it turns out he had something to do with Chandra's disappearance." Shauna Cone, 23, who works in retail, is a friend of Levy. Cone does not consider infidelity alone to be disqualifying for a politician. "To a certain extent it's his own business," she said, "but this situation is different."

Levy's mother, Susan, recalled cautioning her daughter before she headed to Washington last fall for her internship.

"I honestly said, 'Chandra ... don't you become a Monica Lewinsky,"' she said Tuesday. "And look at what happened."