She’s the most recent to make this observation, but not the first. Women have been criticized for lacking in ambition practically since they were told they could be ambitious in the first place. A 1987 study at Pennsylvania State found that women’s lack of ambition prevented them from applying to medical school. According to a 1990 study published in the American Journal of Political Science, women lacked political ambition. And Gloria Steinem notably observed in the 1970s that “some of us are becoming the men we were raised to marry,” a statement that encouraged women to raise their career ambitions. When Steinem said this, women were only at the beginning of a journey that could lead them away from marrying the doctor and toward being the doctor. And yet, 40 years later, some of our college classmates who aspired to high-flying careers instead married men who have those careers.

So how to reconcile all of these seemingly conflicting pieces of data? The ambitious women we’d known in college didn’t seem to have been affected by an ambition gap. They had clearly articulated goals and a path to achieving those goals. But over the course of their careers something had shifted. Was it just their ambition?

A few studies would say yes. A Bain & Co study from 2015 found that women enter their careers with a higher level of ambition than men. But while men’s aspiration levels stay the same for at least the first two years on the job, women’s levels plummet by 60 percent. In a survey conducted by More magazine, 43 percent of the women surveyed reported that their ambition had dropped in the last 10 years.

But this also didn’t sit right with us. When we talked to our former classmates in 2016 who had chosen to scale back or opt out of their careers, they didn’t strike us as any less ambitious than they’d been in college. In fact, after the interviews we often reflected on how wonderful it was to see former friends living lives that they took pride in. These might not have been the lives they’d envisioned for themselves back in college, but that didn’t make them any less valid, and it certainly didn’t make them no longer ambitious. As Anne-Marie Slaughter pointed out in her book Unfinished Business, “The assumption that women are dropping out because of a lack of drive or ambition rests on the deeper assumption that these women could have high-flying careers if they just wanted them badly enough.” We came to see that many of our subjects chose not to pursue that high flight in the professional arena, but continued to soar in nearly every other avenue of their lives.

One woman who had aspired to be an opera star, and then switched to a career in finance before leaving the workforce after her first child was born, said she’d “been the president of everything”: neighborhood associations, school organizations, and charitable groups. We heard this sentiment from many women in our Opt Out group, and those who hadn’t been the president had often created their own organization. A former classmate living in Guatemala organized a volunteer group to help educate impoverished children living at a dump site, who otherwise would have received no schooling. A former lawyer who left the Justice Department to home-school her nine children in rural Colombia, volunteered as a legal advocate for women coffee pickers in a nearby village. She and her children had also begun an informal program to teach the local police English, in an effort to boost tourism. These women’s ambitions clearly hadn’t disintegrated once they became mothers. What about the women who weren’t parents? Some of them became High Achievers, but some actively chose other paths.