Earlier this year, women became the majority of the workforce for the first time in U.S. history. Most managers are now women too. And for every two men who get a college degree this year, three women will do the same. For years, women’s progress has been cast as a struggle for equality. But what if equality isn’t the end point? What if modern, postindustrial society is simply better suited to women?

In the ’90s, when Ericsson looked into the numbers for the two dozen or so clinics that use his process, he discovered, to his surprise, that couples were requesting more girls than boys, a gap that has persisted, even though Ericsson advertises the method as more effective for producing boys. In some clinics, Ericsson has said, the ratio is now as high as 2 to 1. Polling data on American sex preference is sparse, and does not show a clear preference for girls. But the picture from the doctor’s office unambiguously does. A newer method for sperm selection, called MicroSort, is currently completing Food and Drug Administration clinical trials. The girl requests for that method run at about 75 percent.

Even more unsettling for Ericsson, it has become clear that in choosing the sex of the next generation, he is no longer the boss. “It’s the women who are driving all the decisions,” he says—a change the MicroSort spokespeople I met with also mentioned. At first, Ericsson says, women who called his clinics would apologize and shyly explain that they already had two boys. “Now they just call and [say] outright, ‘I want a girl.’ These mothers look at their lives and think their daughters will have a bright future their mother and grandmother didn’t have, brighter than their sons, even, so why wouldn’t you choose a girl?”