Few women are unaware of the proverbial biological clock. As a result, girls often have their educational and professional “plan” in place at an early age to ensure they can enjoy both a career and a family. On the flip side, men, who have the ability to have children late in life, often don’t feel the same pressure. While young women are busy advancing their plans under the loud tick-tock reminder of their biological limitations, many men are enjoying a bromance, video games, the social scene, and slowly getting around to a career.

It seems this difference in family-planning pressures might help explain the increasingly cavernous maturity gap between the genders. If so, recent studies about male fertility could start to change that.

Our modern gender disparities haven’t gone unnoticed. Kay Hymowitz recently described the “alpha girl” — assertive, athletic, ambitious and academically motivated — in her book Manning Up: How the Rise of Women Has Turned Men Into Boys. Women’s success, she suggests, has happened at the expense of boys, who are increasingly being surpassed by the other sex. 

It’s hard to miss the phenomenon. Just look at any recent young-adult comedy like “Knocked Up” or “She’s Out of My League” to watch the now-familiar story unfold: The female interest is smart, successful, beautiful and financially secure, while the male interest is, well, still a work in progress at best. Christina Hoff Sommers recognized this problem more than a decade ago when she wrote The War Against Boys: How Misguided Feminism Is Harming Our Young Men. And even former NOW board of directors chairman Warren Farrell saw the problem percolating when he wrote The Myth of Male Power in 2001.

Perhaps part of the problem is that for years there has been the false assumption that women are the only ones with a biological clock. But a series of new studies (see The Wall Street Journal Wednesday for a roundup) reveals just the opposite. The fact is men bring as much risk to the equation as women. And as women increasingly put off marriage into their late 30s, they’re tending to pair off with older men. But for men even approaching 40, “the incidence of bipolarity, epilepsy, prostate cancer and breast cancer” increases in children. And you can imagine the list of genetic deformities gets far worse with men over 40, and certainly over 50.

In short, women are born with all their eggs. While they lose eggs as they age, the genetic material in them was that created in utero. Men, on the other hand, replicate their sperm regularly; but quality degrades with each copy, leading to genetic problems as they age.

So how might this affect gender relations? Will this new revelation about fertility begin to shift the way our culture, and the young men and women in it, think about their lives, their plans for a career and family? Will men take time and growing up more seriously? Will women eager to have children become more reluctant to pair up with men 10 or 20 years older? Will men decide their extended adolescence might not be a great idea for their long-term survival?

Despite all the professional gains women have made in recent decades, they have too often been on the losing end of the “man-child” phenomenon. My suspicion is that might be about to change.