Charisma comes from the Greek word for “divine gift,” and back in 2015, political commentators thought Elizabeth Warren had a lot of it. Vox called the senator from Massachusetts “a more charismatic campaigner than [Hillary] Clinton.” Roll Call said Clinton couldn’t “match Warren’s charisma, intensity or passion.” The polling firm Rasmussen called Warren “Bernie Sanders with charisma.”

That was then. Now that Warren is running for president, many journalists have decided the charisma is gone. An article last month in The Week noted that Warren “doesn’t do uplift, which is what people mean when they grumble about her lack of ‘charisma’ and ‘energy.’” In a recent story about Warren’s fundraising trouble, The New York Times suggested that she was suffering because Democrats’ “longstanding fascination with youthful charisma—along with its current, Trump-driven fixation on electability—can outweigh qualities like experience or policy expertise.”

What happened? Warren may be a victim of what scholars of women’s leadership call the “double bind”: For female candidates, it’s difficult to come across as competent and charismatic at the same time. To be considered charismatic, leaders must be both appealing and inspiring, both likable and visionary. Unfortunately for women who seek positions of power, they’re rarely perceived as possessing these characteristics while also being deemed competent to do the job.

Since announcing her campaign for the 2020 Democratic presidential nomination, Warren has worked harder than any other candidate to prove she’s ready to govern. She’s laid out proposals on taxation, government corruption, prescription drugs, housing, and even “postal banking,” all of which has led the Times to describe her strategy as “Stand Out by ‘Nerding Out.’”

To academics who study women leaders, this wouldn’t come as a surprise. Catalyst, a research group focusing on women’s experience in the workplace,has noted that, compared with men, “women spend additional time during work hours proving they are competent leaders.” The reason, according to a 2010 study by Victoria Brescoll and Erica Dawson of Yale University and Eric Luis Uhlmann of INSEAD, is that women in traditionally male jobs “are penalized more harshly for making mistakes. Their status and competence [are] fragile and more easily revoked.”

But in seeking to bolster their fragile reputation for competence, women can undermine their aura of charisma in two separate ways. First, they become less likable. As Susan Fiske, Amy Cuddy, and Peter Glick have illustrated, women in traditional roles—say, housewives—are generally perceived as warm but incompetent. But women who defy these traditional stereotypes and prove their competence in a male-dominated sphere—say, women soldiers, businesspeople, or politicians—are frequently deemed cold and unfriendly.

That’s what happened to Hillary Clinton, who, like Warren, was renowned for her hard work and devotion to policy detail. In exit polls, 90 percent of voters who said “the right experience” was their most important criterion supported Clinton. But a majority viewed her negatively nonetheless. (Michelle Bligh, a professor of organizational behavior at Claremont Graduate University, reminded me that, by contrast, Sarah Palin was widely deemed “warm but incompetent.”)

What happened to Clinton is now happening to Warren. FiveThirtyEight has called her “the wonkiest person in the field.” In February, however, when the University of New Hampshire asked Granite State voters which candidate they considered most “likable,” 31 percent chose Joe Biden and 20 percent chose Sanders. Beto O’Rourke, who hadn’t yet announced his candidacy, received 9 percent. Warren, despite being a well-known senator from a neighboring state, garnered only 3 percent.

If being disliked isn’t bad enough, there’s a second, less discussed downside for women who establish a reputation for competence: They’re often considered less inspirational. For a 2009 Harvard Business Review study, Herminia Ibarra of the London Business School and Rice University’s Otilia Obodaru interviewed women business leaders and found that, like Warren, many had built a reputation for competence. The problem was that in taking extra precautions to avoid mistakes, they came across as less visionary. Because women leaders “often lack the presumption of competence accorded to their male peers,” write Ibarra and Obodaru, they “are less likely to go out on a limb, extrapolating from facts and figures to interpretations that are more easily challenged … They adopt a defensive, often rigid, posture, relying less on their imagination and creativity.” Fearful of coming across as insubstantial, they often appear uninspiring.

In mid-level corporate jobs, where vision is deemed less important, this doesn’t hurt women as much, just as it doesn’t take as big a toll on women running for lower political office. But when asked which quality was most important for “overall leadership effectiveness,” executives chose “inspiring others,” the attribute on which women fared worst. That’s why it’s dangerous to extrapolate from the current popularity of a congresswoman such as Alexandria Ocasio-Cortez. The trade-offs between being deemed competent on the one hand and being deemed likable and inspirational on the other grow starker as you get closer to the top job.

Men don’t face the same bind. Think of Barack Obama, who, despite his reserved, professorial demeanor, was widely deemed charismatic. Or, more recently, Pete Buttigieg. When describing Warren, journalists often imply that she must choose between being wonky and being charismatic. As the Times put it early this year, “Warren is making a personal and political wager that audiences care more about policy savvy than captivating oration.” But when describing Buttigieg, journalists suggest no such trade-off. The Washington Examiner recently praised his “authentic charisma, intellect, and policy chops.” Vanity Fair in March commended his “smarts and charisma.”

One apparent exception to this pattern is Kamala Harris, who in February was deemed most likable by 9 percent of New Hampshire voters, below Biden and Sanders but three times as high as Warren. It’s impossible to know for sure why Harris is so far evading the “double bind” between competence and charisma. But research into the different ways people perceive white and black women might offer a clue.

On the one hand, African American women pay an even higher price for appearing incompetent than do white women. In a 2012 study, Ashleigh Shelby Rosette of Duke University’s Fuqua School of Business and Robert Livingston of Harvard’s Kennedy School of Government found that “black women are more harshly evaluated under conditions of organizational failure when compared with black men, white men, and white women.”

If, however, African American women meet the extra high bar required for them to reach top leadership positions, the negative side effects that plague white women leaders might harm them less. The reason, as Rosette, Livingston, Christy Zhou Koval, and Anyi Ma found in a 2015 study, is that black women were less likely than white women to be stereotyped “as warm, showing concern for others, or cooperative.” To the contrary, black women were frequently “perceived as dominant and strong.” Thus, when black women leaders take actions that make them appear dominant, they might face less of a “backlash for counter-stereotypical behavior.” They’re not penalized as much for acting against gender stereotype because the stereotypes attributed to them are different.

In an interview, Rosette emphasized that for black women, there’s a big difference between being perceived as dominant and strong and being perceived as angry—and cited the harsh reaction when Serena Williams last year called an umpire a “liar” and a “thief.” But in the committee hearings where Harris has interrogated Trump officials, as well as in her campaign, she appears to have walked that line successfully so far while also avoiding the perception of incompetence, which could prove particularly damaging to a black woman candidate.

Warren’s troubles, on the other hand, are being compounded by journalists who analyze her image without recognizing how bound up it is with her gender. The media aren’t responsible for the fact that many male, and some female, voters demand that women presidential candidates work so much harder to prove their competence—and then react negatively once they do so. But journalists have an obligation to explain what’s going on.

On Sunday, The Washington Post became the latest publication to contrast Warren’s “policy nerd” campaign with those of opponents who “may lay a greater claim to charisma.” But why can’t policy nerds be charismatic? The academic research is clear: They can. It’s just easier when the nerds are men.