It’s not just women — men have biological clocks that tick away too, studies have shown, giving them baby fever and compelling them to create families with increasing urgency over time. Sure, men’s reproductive clocks might tick a bit differently. But the biological imperative to procreate on a deadline is there, alright.
“Gender and baby longing is a question of degrees, not of exclusive categories,” according to the authors of one 2011 study on the subject. “Men may experience a ‘slight rise of temperature’ if not full-blown ‘baby fever’.”
It makes sense that humans, like any animal, would feel a drive to propagate their own genes. But it has long been an article of faith, rather than science, that women feel more pressure to do so than men due to their reproductive limitations. Men can, in theory, reproduce forever. Menopause ends that possibility, for women.
Indeed, researchers have found that male baby fever presents differently than female baby fever. While women desire children less as time goes on, men want more progeny as they age and begin building families. “How frequently women have the desire to have a child goes down with age, and down as they actually have children,” Gary Brase, a psychologist at Kansas State University who’s studied baby fever in men, told LiveScience.
“For men, it tends to go up.”
One thing that seems to make a man’s biological clock tick is, well, women. National studies of Finnish couples have found that baby fever in men typically arises during conscious attempts to conceive, which are often dictated by the woman’s desire to have a baby. Simply put, baby fever is contagious. One recent study supports this notion. Researchers found that younger women paired with older men were less fertile than expected, and older women paired with younger men were more fertile than expected. Laura Dodge, a professor of reproductive biology Harvard Medical School who led the research, suspects that this is because couples—men and women—that consist of a woman reaching the end of her reproductive life feel more pressure to conceive.
“The impact of age seems to focus almost exclusively on the female partner’s biological clock,” Dodge told The Guardian. “When making this decision, they should also be considering the man’s age.”
Another factor, observed by Brase and colleagues in U.S.-based samples, is a simple cost-benefit analysis. As men grow older they tend to achieve more in their careers, so the costs of having a child (financial and professional) diminish, relative to the benefits. Baby fever may be less about gender than socioeconomics. “Gender role norms didn’t do much as far as explaining people’s desire to have a baby,” Brase says.
It’s important to note that some men in the research did not need to have partners who wanted children in order to experience baby fever. For men like them, it’s possible their biological clocks are powered by the need to assert their masculinity, a part of the male identity that researchers suspect needs to be proved on a regular basis. Providing, protecting, and procreating are three core cultural dimensions of masculinity, after all.
Which means there’s nothing more masculine than catching baby fever.