How to overcome subtle sexism at work

FORTUNE -- Was it just me, or did anyone else have the fleeting thought when newly re-elected Ohio Republican John Boehner got all teary-eyed during his victory speech, that if a woman had choked up like that, the pundits would be sounding alarm bells about her mental stability?

Remember when Hillary Clinton famously fought back tears on the campaign trail in New Hampshire while running for the Democratic presidential nomination? The media made a meal of it for days, speculating about whether Clinton was about to crack up or get carried away by her hormones.

There was no such reaction to Rep. Boehner's show of emotion: Commentators either barely mentioned it, or else took a fond, "aw-shucks-ain't-that-sweet" view of the waterworks.

What makes that response, or lack of one, even more surprising is that our longstanding definition of masculinity discourages men from expressing strong feelings, or from seeming to lose control over them.

Women in executive jobs, or who aspire to be, are all too familiar with this kind of double standard. People seem quick to question whether a woman is really ready to lead even when -- in a wide range of situations, not just those involving tears -- the same behavior by a man raises few eyebrows.

Obviously, women have come a long way in the past couple of decades, but a subtle bias is still woven into the culture, which paradoxically makes it tougher to fight than the old-fashioned, in-your-face sexism of yore. How do you tame the elephant in the room when no one will admit there's an elephant?

First, says a new book called Her Place at the Table: A Woman's Guide to Negotiating Five Key Challenges to Leadership Success, you learn the unspoken codes.

From their own extensive experience and interviews with more than 100 female luminaries in business and politics, authors Deborah Kolb, Judith Williams, and Carol Frohlinger have culled what they call "unarticulated yet persistent questions" about women's leadership ability.

To some extent, the authors argue, women themselves are to blame for not doing enough to advance their own interests and stick up for their achievements. No matter how accomplished and valuable you are, you'll never get anywhere until you learn how to negotiate.

Her Place at the Table is a down-to-earth guide to doing just that, and it's packed with examples of situations many women will recognize. To take just one, let's say you put in a lot of effort that tends not to show up on the corporate radar, such as mentoring younger colleagues, training new hires, and recruiting top talent. It's important work, not to mention time-consuming, but it's not part of your job description, so it isn't reflected in your performance review -- or your raise.

Wake up! The authors recommend you do the math: What would the company have had to pay a coach if you hadn't acted as a mentor? How much would formal training have cost? Who would have recruited these hotshots if you hadn't, and what would that headhunter have billed the company?

It all adds up.

"All the women we interviewed wanted to have a positive impact on their organizations. And indeed, many of them did. The challenge for women may not be making a difference. Instead, it may be getting credit for what they do," the authors write.

Of course, men don't always get credit for everything they contribute to a company's success, either. But at least men are usually aware that their contributions are, in fact, valuable. More importantly, they're generally more willing than women to do the sometimes dicey and delicate work of negotiating for the recognition and rewards they've earned.

That is a big reason why men at the same education level and with the same jobs are still paid more than women. And it may also be why men are allowed to shed a tear or two every now and then without anyone questioning whether they can handle their hard-won power.