Ask people why women remain so dramatically underrepresented, and you will hear from the vast majority a lament—an unfortunate but inevitable “truth”—that goes something like this: High-level jobs require extremely long hours, women’s devotion to family makes it impossible for them to put in those hours, and their careers suffer as a result. We call this explanation the work/family narrative. In a 2012 survey of more than 6,500 Harvard Business School alumni from many different industries, 73% of men and 85% of women invoked it to explain women’s stalled advancement. Believing this explanation doesn’t mean it’s true, however, and our research calls it seriously into question.

We heard this explanation a few years ago from a global consulting firm that, having had no success with off-the-shelf solutions, sought our help in understanding how its culture might be hampering its women employees. The firm recruits from elite colleges and MBA programs and ranks near the top of lists of prestigious consultancies, but like most other professional services firms, it has few female partners.

We worked with the firm for 18 months, during which time we interviewed 107 consultants—women and men, partners and associates. Virtually everybody resorted to some version of the work/family narrative to explain the paucity of female partners. But as we reported last year with our colleague Erin Reid, the more time we spent with people at the firm, the more we found that their explanations didn’t correspond with the data. Women weren’t held back because of trouble balancing the competing demands of work and family—men, too, suffered from the balance problem and nevertheless advanced. Women were held back because, unlike men, they were encouraged to take accommodations, such as going part-time and shifting to internally facing roles, which derailed their careers. The real culprit was a general culture of overwork that hurt both men and women and locked gender inequality in place.

What People Told Us—and What the Data Showed

On several dimensions, the firm’s data revealed a reality very different from the story employees told us—and were telling themselves. The disconnects we observed made us question why the story had such a powerful grip—even on the firm’s data-minded analysts, who should have recognized it as a fiction.

Consider retention. Although one of the firm’s motives for reaching out to us was that it wanted help addressing “women’s higher turnover rate,” when we took a careful look at its data for the preceding three years, we discovered virtually no difference in turnover rates for women and men.

Another disconnect: Whereas firm members attributed distress over work/family conflict primarily to women, we found that many men were suffering, too. “I was traveling three days a week and seeing my children once or twice a week for 45 minutes before they went to bed,” one told us. He recalled a particularly painful Saturday when he told his son he couldn’t come to his soccer game. “He burst into tears,” the man said. “I wanted to quit then and there.” Two-thirds of the associates we talked to who were fathers reported this kind of work/family conflict, but only one was taking accommodations to ease it.

Accommodations were another area in which the firm’s narrative and its data didn’t line up. Employees who took advantage of them—virtually all of whom were women—were stigmatized and saw their careers derailed. The upshot for women at the individual level was sacrifices in power, status, and income; at the collective level, it meant the continuation of a pattern in which powerful positions remained the purview of men. Perversely, in its attempt to solve the problem of women’s stalled advancement, the firm was perpetuating it.

We also found incongruities within the work/family rhetoric itself. Take the way this man summed up the problem: “Women are going to have kids and not want to work, or they are going to have kids and might want to work but won’t want to travel every week and live the lifestyle that consulting requires, of 60- or 70-hour weeks.” Resolute in his conviction that women’s personal preferences were the obstacle to their success, he was unable to account for such anomalies as childless women, whose promotion record was no better than that of mothers. In his calculation all women were mothers, a conflation that was common in our interviews. Childless women figured nowhere in people’s remarks, perhaps because they contradict the work/family narrative.

In a final disconnect, many of those we spoke with described experiences that called into question the work/family narrative’s foundational premise: that 24/7 work schedules are unavoidable. They talked about devoting long hours to practices that were costly and unnecessary, chief among them overselling and overdelivering. We heard many stories of partners who, as one associate put it, “promise the client the moon” without thinking of how much time and energy it takes to deliver on such promises. The pitch goes like this, he explained: “We’ll do X, Y, and Z, and we’re going to do it all in half the time that you think it should take.” Clients are wowed and can’t wait to sign up, he told us.

Associates felt pressured to go along with these demands for overwork because they wanted to stand out as stars amid their highly qualified colleagues. ‘‘We do these crazy slide decks that take hours and hours of work,” one said. “It’s this attitude of, ‘I’m going to kill the client with a 100-slide deck.’ But the client can’t use all that!’’ Another associate ruefully described all the weekends she had devoted to these sorts of tasks. “I just worked really, really hard,” she told us, “and sacrificed family stuff, sacrificed my health for it, and at the end of the day, I look back on it, ‘Well, did we really have to do that? Probably not.’”