This isn’t reasonable doubt.

Recommendation letters for women are more likely to contain “doubt raisers” — words or phrases that cast doubt on an applicant’s suitability for a professional or academic opportunity — than letters of recommendation for men, a new study from Rice University, the University of Houston and CUNY found.

“We’re seeing a lot of overt types of discrimination on the rise, and I think we also shouldn’t forget that there are subtle forms as well,” study co-author Mikki Hebl, a psychologist at Rice, told Moneyish. “Some of our research suggests that the subtle forms can be just as pernicious as the overt forms.”

These doubt raisers might include phrases like “might make a good colleague,” “has the potential to be successful” and “despite the fact that she had a lot of difficulty getting there, she’s pretty good,” Hebl said. “Though they may vary in the degree of negativity and subtleness, they all potentially raise doubts for the evaluator because they indicate that the writer is uncertain about the applicant, or does not have an entirely positive impression of the applicant,” the researchers wrote.

Doubt raisers can take the form of negativity (drawing attention to an overt weakness), hedging (e.g., “might not be the best”), faint praise (e.g., “needs only minimum supervision”) and irrelevant information, according to the paper published in the Journal of Business and Psychology.

Also read: Even judges aren’t immune to gender bias, a new study shows

In their first study analyzing recommendation letters for applicants to faculty positions at a university psychology department, the researchers established that letters written for women bore more doubt raisers — negativity, faint praise and hedges, namely — than did letters for men. (The findings held true even after controlling for productivity.) In a second study, the authors used a sample of university professors to determine that regardless of gender, negativity and hedging in a letter resulted in lower evaluations of applicants.

Doubt raisers were negatively perceived in letters for both men and women, Hebl noted, but they cropped up more often for women. “Taken together, the key contribution of these studies is the clear illustration that doubt raisers in letters of recommendation do indeed hurt women more than men,” the authors wrote, “but only because doubt raisers are more frequent in letters for women.”

Hebl, who says she writes up to 100 letters of recommendation for people every year, suggested recommendation writers go back through past letters to see if they’ve used any doubt raisers — and use that newfound awareness going forward. “(If) we become aware of these subtle biases,” she said, “we can actually change them.” She also urged them to look out for describing women with “communal” words — i.e. caring words like “kind” and “sensitive” — rather than more “agentic” words that convey strength and power.

“In the contest between being liked and being respected, you always want to be respected,” Hebl said. “So for me, it’s about making sure that my letters of recommendation that I write for women are about conveying messages that they should be respected.”

She also advised letter seekers to provide a rundown of accomplishments, talking points and reminders of what they want the recommender to address in the letter. “I like to put some of the burden of that on the person for whom the letter’s written,” she said, “because then it assures them that they are articulating the things that are most agentic about themselves.”

Also read: 42% of working women say they’ve been discriminated against at work

If providing bullet points to your recommender feels awkward or intrusive, you might find a subtler way in. Marketing strategy consultant Dorie Clark offered one such approach: “I know sometimes it can be tricky to know what kinds of things to mention. Obviously I want you to say whatever you feel is appropriate and true, but if it would be helpful, I have a quick, one-page document that I put together with some talking points … that might serve as informational reference points for you,” she suggested. “And then they can tell you if it would be helpful or not.”

Think carefully about whom you ask for the recommendation, Clark added. Choose someone who knows your work well and likes you, of course, but also “think about who in your orbit knows how to speak like the people who are the hiring managers” — and instinctively understands the kinds of skills, qualities and characteristics the evaluators will be looking for.

Temperament matters, too. So if you’re angling for a gig as a junior investment analyst, Clark said, it might not help to hear that you’re “so creative” and bring “such a positive vibe to the company.” And if you’re trying to break out of finance and into the nonprofit world, describing you as an “aggressive employee” with a “take-no-prisoners style” could also backfire.

“If you have chosen someone who is dispositionally dissimilar to the type of industry that you’re applying for a job in, even the things that they think are positive about you or the way in which they go about trying to convey these positive things may be warning signs to the new firm that you won’t fit in,” Clark said, “because they’re expressing them in such a dramatically different way than what they’re used to.”