Once upon a time -- several decades ago -- there was a clear divide between the roles of mothers and fathers. Mothers stayed home and took care of the kids and fathers went to work.
All of that changed when women began entering the work force in droves. According to the Census Bureau, in the last four decades the number of mothers who became working mothers doubled to 80 percent, and the lines between the sexes began to blur.
But while women became more like men, men have been slower to break from their traditional roles -- until now.
Bryan and Lisa Levey are the kind of couple who show just how different times are now -- and how similar gender roles have become. The Lexington, Mass., couple, both in their mid-40's, have two children, Skylar, 10, and Forrest, 6. And both share responsibility for raising them.
"I think we are co-parents," says Lisa Levey, "and we have been from day one."
Sociologists have a different term for it: gender convergence.
"Gender convergence is the notion that men's and women's lives are becoming more and more similar," says Barbara Risman, a professor of sociology at the University of Illinois.
Both Bryan and Lisa cook and do laundry, chauffeur the kids and help with homework, and both have careers that they consciously try to balance with the demands of raising a family.
"There's less pressure on her to be the primary caregiver, and there's less pressure on me to be the primary breadwinner," says Bryan. "Having the work-life balance is very critical to both of our happiness."
That's not the kind of thing you would have heard from a man back in the days of "Leave It to Beaver" and "Father Knows Best."
"Women have talked for a long time about struggling and how do you balance your responsibilities as a parent and a worker," said Risman. "I think the difference now is that men are beginning to struggle with these responsibilities."
When it comes to managing the demands of career and family, most working mothers and fathers now crave the same thing.
These days, both parents want less time at the office and more at home. And fathers are spending more time with their children: On average, they're at home with them 33 hours a week, up from 26 hours a week a generation ago.
Fathers are "more likely to be willing to say, 'It's 5 o'clock or 6 o'clock, and I can't stay for that meeting. I have to pick up my kid at day care,'" says Risman, who also believes men are less likely to be stigmatized for wanting to be home more with their children.
"And if there is the fear of stigma," she adds, "I think they're more willing to say, 'This is important to me.'"
Yet the time at home does not come without a cost. For eight years, Bryan spent more time at home by working a four-day week, and he gave up at least one big promotion to do it.
"Who knows?" says Bryan. "Maybe I could have been at the top of a business at a young age, but I probably wouldn't have been very happy, so what's the point?"
Plenty of working mothers have asked the same question. The genders converge -- once again.