Parenthood seems to require average men and women to spontaneously develop superhuman capabilities--such as the ability to act like a normal person on only a couple hours of sleep, reported Inc.

And while it's intuitive to think that this hyperactive state can be distracting and detrimental to a person's professional pursuits, the opposite can be true, suggests a recent study.

The Federal Reserve Bank of St. Louis looked at the productivity of men and women with and without families over the course of 30 years. After analyzing data from 10,000 individuals, the study's authors concluded that men and women with two or more children are more productive over the course of a career than those with one or no children.

How about that?

In order to measure work productivity, researchers chose to look at academia, a field where achievements are more quantifiable than in others.

"For most other highly skilled professionals, such as managers, engineers, surgeons, top officials, and so on, comparable productivity measures are either not available or not recorded," the researchers explained.

Then to carry out their research, they looked specifically at economists' publication records in conjunction with their answers from an anonymous survey.

The researchers found that the effect of parenthood on women's and men's productivity was different--namely in the way it affected mothers of young children. These mothers saw an initial loss in productivity.

However, over an entire career, "mothers of at least two children are, on average, more productive than mothers of only one child, and mothers in general are more productive than childless women," the authors wrote.

Of course, the study has limitations. Most notably, it looks at a group of highly educated individuals who likely have the resources to plan their families carefully, wrote The New York Times's KJ Dell’Antonia. Plus academics usually enjoy more flexible work schedules than most men and women their age in other fields.

But perhaps that's where the lesson lies.

"What the study does, though, is reinforce the idea that flexibility, however it's possible within a given workplace, can lead to more productivity, not less," Dell’Antonia said.