Not all jobs are glamorous, but a lot of jobs entail glamour work, the kind of work that leads to promotions—and, as Joan C. Williams and Marina Multhaup have found, the kind of work that is disproportionately denied to women and people of color.

As Williams and Multhaup write in Harvard Business Review, glamour work “gets you noticed by higher-ups, gives you the opportunity to stretch your skills with a new challenge, and can lead to your next promotion. It’s the project for a major client, the opportunity to build out a new team, or the chance to represent the company at an industry conference.”

Then you have office housework, work that is necessary but goes unsung, as these researchers assert: “Some is administrative work that keeps things moving forward, like taking notes or finding a time everyone can meet. Some is emotional labor … Some is work that’s important but undervalued, like initiating new processes or keeping track of contracts. This kind of assignment has to get done by someone, but it isn’t going to make that person’s career.” (And some of this office housework is actual housework, like getting coffee or cleaning up a meeting room.)

To test who was getting what assignments, these researchers developed a Workplace Experiences Survey and honed in on the engineering and law professions. And their findings showed some serious imbalance. Amid engineers, for example, women were 29% more likely than white men to report doing more office housework than their peers. And amid lawyers, women of color were more than 20% more likely than white men to report doing administrative tasks, and white women were 18% more likely.

As for glamour work, female engineers of color were 35% less likely and white female engineers were 20% less likely to report having equal access to desirable assignments. And female lawyers of color were nearly 30% less likely and white female lawyers were 18% less likely than white men to report an even playing field regarding high-quality assignments.

Furthermore, the anecdotal evidence from these researchers’ surveys shows patriarchal biases you’d expect from Mad Men, not a workplace in the 21st century. Said one female lawyer: “Despite superior educational credentials and being a lateral transfer from a far more prestigious firm, I was given an appropriate title but slotted into the subservient, support role (i.e. expected to take notes, get coffee, hang men’s jackets, etc.).”

And here’s a report from an engineer: “Just last year they hired a new female, and one of the managers was telling me how happy they were about hiring her because she really cleans up after the guys and keeps the lab tidy.”

The researchers attribute these biases and inequities to gender and racial stereotypes—including, for example, the perception that women are modest and helpful and they always say yes. And these stereotypes put social pressure on women and people of color. For example, they feel obligated to take on the housework lest they be accused of not being a “team player.” Another insidious stereotype is that women don’t want the glamour work and that they’re happy playing supportive roles, but Williams and Multhaup’s research shows female employees are indeed ambitious and hungry for those high-reward assignments, as are employees of color.

Plus, this research provides even more proof of the maternal wall bias—the negative assumptions that haunt women who become mothers mid-career, assumptions propagated by employers who believe these women are somehow less committed and less competent. Here’s what one white female lawyer had to say: “I made partner in the shortest time of any female. Things were great. I had my son. I worked part-time during leave and came back in nine weeks. My work was gone. It has taken two years and a change in focus to get back to the level I was at.”

Williams and Multhaup do provide vital tips for managers, though. For one, they recommend creating a system so that everyone in the organization chips in to tackle office housework, even if employees claim “I’m just not a details guy” or “Women are more organized.” And they recommend considering all eligible employees for the glamour work, even if an arbitrary system or a rotation has to be put in place. And if there aren’t enough eligible employees, that’s an opportunity for managers to invest in the skill-building of less experienced workers.

After all, distributing the work fairly is just good business sense, as Williams and Multhaup argue. “An equitable assignment system means that companies will be tapping into a broader talent pool,” they write, “one that has been right under their nose the whole time, stocked with overlooked expertise.”