toot your own hornThink hard: When’s the last time you took credit—really took credit—for a job well done? Without giving props to others, shying away from praise, or otherwise shifting the recognition to anyone but yourself?

A May 2013 study published in the Personality and Social Psychology Bulletinfound that women who work with men are far less likely to take credit for their work than those who collaborate with other women. Instead, women in mixed-gender work teams tend to give more credit than is necessary—or even true—to their male colleagues. This is habitual: Instead of talking about themselves in an honest way, women give away the credit, talking about the great team they had, the collaborative efforts involved, the talents of someone, anyone, else. In some instances, women will even point to the negative aspects of themselves or their achievements instead of simply saying “thank you” or otherwise owning potential praise. Sound familiar?

Why is this? It’s complicated. It could be that women are more natural sharers or group participants, used to a hard-to-shake “we” mentality over an “I” mentality. It could also be that women, when paired with male partners, devalue their contributions because, well, that’s what work culture in many ways still seems to do. The study also suggested the rising incidence of the Imposter Syndrome, in which high-achieving people (mostly women) don’t feel they deserve the success that they have earned. And so they divert the credit onto others—namely, the men in the group.

Molly, a junior art director at a city magazine, found this to be true when a magazine cover she’d conceived and designed went viral. The resulting attention was being lavished on her entire department, but especially her male superior. “It was a team effort, sort of, in that we all work as a ‘unit’ to create a single product, the magazine,” she told me. “But the idea was mine. I thought of it and I executed it. I didn’t speak up because I tried to tell myself I’d only done my job on behalf of the team, but in the end everyone assumed it was a single person’s idea, specifically my male boss’s. He didn’t take the credit, but he didn’t deny it, either.” And yet, she told me, “I felt like it would be sort of arrogant and boastful to speak up and say, hey, I did this.”

But boastful is what helps workers get ahead. A 2012 report from management consulting firm Accenture called “The Next Generation of Working Women” found that women are less likely to speak up than men, less likely to proactively manage their own careers, and less likely to ask for a raise. According to an NPR report that aired last year, the last fact can mean anywhere from $1 million to $1.5 million in lost earnings over a woman’s lifetime. Owning up to your accomplishments isn’t about arrogance; it’s about equality.

Read more at FORBES.COM