Studies about gender, family, and the workplace inevitably bring out the Neanderthals in American media. This week has been no exception.

On Wednesday, the Pew Research Center released a report on “Breadwinner Moms”—women who are the primary or the only income earners in their families. As you might expect, they are a lot more common than they used to be. In 1960, just 11 percent of families had moms as their primary breadwinners. Today, 40 percent do.

Is this a crisis—a violation of the natural scientific order? Erick Erickson, the conservative blogger, thinks so. Appearing on a Fox News panel, he explained:

When you look at biology, look at the natural world, the roles of a male and female in society, and the other animals, the male typically is the dominant role. The female, it's not antithesis, or it's not competing, it's a complimentary role. We as people in a smart society have lost the ability to have complementary relationships in nuclear families, and it's tearing us apart.

My own views are a little different. My wife has earned more than I have for most of the 18 years we’ve been married. And I have to tell you—it’s pretty awesome. At various points in our lives, her job has been our source of health benefits, childcare, and even football tickets. Not everybody feels the same way about such arrangements, I realize. But, as Pamela Smock, a sociologist at the University of Michigan, pointed out via e-mail, the Pew data (which included public opinion) suggests more and more people seem to think like I do—and less like Erickson does. “Younger adults are more gender egalitarian than older adults,” Smock, who is also director of the university’s Population Studies Center, said. “The report provides important and compelling evidence of a continuing shift in this direction. I expect this trend towards gender egalitarian views to continue.”

Still, the rise in women as the primary breadwinner isn’t simply a product of women establishing careers and, finally, getting paid well for them. Of the families in which women were the primary source of income, two-thirds are families in which women are also the only source of income—frequently because they are raising kids on their own. There’s a sharp, discernable class divide here: Lower income mothers are more likely to be single mothers than their better educated, better paid counterparts.