The New York Times

WASHINGTON — There was a collective rolling of the eyes and a distinct sense of “Here we go again” among the women of the House of Representatives last week when yet another male politician, Representative Anthony D. Weiner, confessed his “terrible mistakes” and declared himself “deeply sorry for the pain” he had caused in sexual escapades so adolescent as to almost seem laughable.

“I’m telling you,” said Representative Candice Miller, a Michigan Republican, “every time one of these sex scandals goes, we just look at each other, like, ‘What is it with these guys? Don’t they think they’re going to get caught?’ ”

Ms. Miller’s question raises an intriguing point: Female politicians rarely get caught up in sex scandals. Women in elective office have not, for instance, blubbered about Argentine soulmates (see: Sanford, Mark); been captured on federal wiretaps arranging to meet high-priced call girls (Spitzer, Eliot); resigned in disgrace after their parents paid $96,000 to a paramour’s spouse (Ensign, John);  or, as in the case of Mr. Weiner, blasted lewd self-portraits into cyberspace.

It would be easy to file this under the category of “men behaving badly,” to dismiss it as a testosterone-induced, hard-wired connection between sex and power (powerful men attract women, powerful women repel men). And some might conclude that busy working women don’t have time to cheat. (“While I’m at home changing diapers, I just couldn’t conceive of it,” Senator Kirsten Gillibrand, the New York Democrat, once said.)

But there may be something else at work: Research points to a substantial gender gap in the way women and men approach running for office. Women have different reasons for running, are more reluctant to do so and, because there are so few of them in politics, are acutely aware of the scrutiny they draw — all of which seems to lead to differences in the way they handle their jobs once elected.

“The shorthand of it is that women run for office to do something, and men run for office to be somebody,” said Debbie Walsh, director of the Center for American Women and Politics at Rutgers University. “Women run because there is some public issue that they care about, some change they want to make, some issue that is a priority for them, and men tend to run for office because they see this as a career path.”

Studies show that women are less likely to run for office; it is more difficult to recruit them, even when they have the same professional and educational qualifications as men. Men who run for office tend to look at people already elected “and say, ‘I’m as good as that,’ ” said Jennifer Lawless, director of the Women and Politics Institute at American University here. “Women hold themselves up to this hypothetical standard no candidate has ever achieved.”

And so, despite great inroads made by women, politics is still overwhelmingly a man’s game. Data compiled by Rutgers shows women currently hold 16.6 percent of the 535 seats in Congress and 23.5 percent of the seats in state legislatures. There are 6 female governors; of the 100 big-city mayors, 8 are women.

Once elected, women feel pressure to work harder, said Kathryn Pearson, an expert on Congress at the University of Minnesota. Her studies of the House show that women introduce more bills, participate more vigorously in key legislative debates and give more of the one-minute speeches that open each daily session. In 2005 and 2006, women averaged 14.9 one-minute speeches; men averaged 6.5.

“I have no hard evidence that women are less likely to engage in risky or somewhat stupid behavior,” Ms. Pearson said. “But women in Congress are still really in a situation where they have to prove themselves to their male colleagues and constituents. There’s sort of this extra level of seriousness.”

And voters demand it. Celinda Lake, a Democratic strategist, says female politicians are punished more harshly than men for misbehavior. “When voters find out men have ethics and honesty issues, they say, ‘Well, I expected that,’ ”  Ms. Lake said. “When they find out it’s a woman, they say, ‘I thought she was better than that.’ “

Of course, it is a big leap to suggest that voter expectations and an “extra level of seriousness” among women in public office translate into an absence of sexual peccadilloes. Helen Fisher, an anthropologist at Rutgers, said her studies on adultery show that, at least under the age of 40, women are equally as likely to engage in it as men. She theorizes that perhaps women are simply more clever about not getting caught.

Female politicians are not immune to scandal in the sex department. Nikki Haley, the South Carolina governor, was accused of adultery last year while running for office; she denied it, and was elected. Helen Chenoweth-Hage, the late Republican congresswoman from Idaho, once confessed to a six-year affair with a married man.

There have even been “crotch shot” allegations; when Barbara Cubin, then a state legislator in Wyoming, ran for the House in 1994, Democrats accused her of “lewd pranks,” including photographing male colleagues’ crotches and distributing penis-shaped cookies. She later said the cookies were a gift from someone else and dismissed the picture charges as scurrilous. Still, all of that seems tame compared to the recent string of spectacular Weiner-like implosions, and here in Washington and around the country last week, there was considerable speculation as to why.

Dee Dee Myers, a press secretary to President Bill Clinton (who managed to survive his sex scandal) and the author of “Why Women Should Rule the World,” surmises that male politicians feel invincible. It would be impossible, she said, to imagine Nancy Pelosi, the former House speaker, doing anything like what Mr. Weiner did.

“There are certain men that the more visible they get, the more bulletproof they feel,” Ms. Myers said. “You just don’t see women doing that; they don’t get reckless when they’re empowered.”

Whatever the reason, it was perhaps no coincidence that it was a woman — Representative Allyson Y. Schwartz of Pennsylvania – who last week became the first Democrat to call on Mr. Weiner to resign. Ms. Schwartz is the only female member of her state’s Congressional delegation, and she says that her Pennsylvania colleagues joke and talk in a different way when she is in the room.

“Having a woman in that mix changes the dynamic,” she said, “and it’s actually not even subtle. It’s very obvious.”