When it comes to parents’ sleep, there’s a lot of focus paid to mom. Don’t get me wrong: mothers’ sleep deserves all the attention it gets. But fathers face sleep challenges, too. And in the scientific world, they’re much less well investigated than moms’ sleep issues are.

With Fathers’ Day approaching fast, I was curious about what science has to say about how parenthood affects dads’ sleep and how sleep problems might affect fathers’ parenting choices. While there’s no shortage of research looking at the impact of sleep on men, I discovered there are relatively few studies that look specifically at dads.

Still, what’s there suggests that dads—especially new and first-time dads—are losing a whole lot of shut eye, thanks to parenthood.

  • A 2016 study published in the U.K. found that dads of young children (for this particular study, that meant kids ages 4 and under) getting less sleep than moms. Among the group of mom-dad pairs in the study, 43 percent of dads said they slept no more than six hours a night, compared to 38 percent of moms.
  • Here in the U.S., scientists from West Virginia University found first-time dads getting less sleep than their mom partners—even though moms were awakened more during the night. The dads also appeared to get hit harder by daytime sleepiness than the moms did, according to the scientists’ objective measurements. (The moms and dads reports about their fatigue showed they felt about the same degree of sleepiness during the day.)
  • A larger study by researchers at University of California, San Francisco came to some similar conclusions: new dads got less sleep overall than new moms. This study suggests a reason why. Moms in the study actually slept less during the night than dads did—but the mothers seemed to be able to make up some of that lost sleep during the day, while at home taking care of their newborns. The dads in the study didn’t have the same opportunity to catch up on their lost sleep.

Remember those relationship skills that are affected by sleep? When we’re tired, we’re less understanding, appreciative, and empathetic with our partners. The sleeplessness of new parenthood challenges those skills, according to research.

A study about perceptions between new, first-time parents found that moms underestimated how often dads woke up during the night and overestimated how well dads were sleeping.

Meanwhile, Dads underestimated how much time moms spent awake during the night. They overestimated the degree to which moms were in a bad mood.

Before we go revising entirely the conventional wisdom about which parent has a harder time with sleep, there’s this: a big, national survey found that it is moms who are getting shortchanged on sleep, more than dads. Moms are also substantially less likely to get a full 7 hours of sleep than women without children. (Shocking, I know.)

Both dads and moms stand to have their parenting approach affected if they don’t get enough sleep. That’s the takeaway from some new research showing that a lack of sleep makes both fathers and mothers less strict than well rested ones.

Dads could do worse than being given the gift of a little extra sleep on Fathers’ Day weekend.

Written by Caitlin Reynolds