Sleeping in separate beds sounds like what Grandma and Grandpa did to maintain modesty — or these days, something that happens when you get into a huge fight with your partner and are too ticked off to fall asleep together.But sleeping apart is more common than you might think. A 2013 Canadian study found that 30 to 40 percent of couples choose to sleep in different beds. Another survey, conducted by FiveThirtyEight.com with the help of SurveyMonkey, showed that almost half of the respondents reported sleeping apart from their partner at least once, while 14 percent of couples said they sleep separately every night.That may sound like their relationships are falling apart — but the opposite may be true.”Everybody is operating on a sleep deficit — whether it’s because you’re stressed or you’re pregnant or have kids,” pointed out Rachel Sussman, a relationship therapist in New York City and author of The Breakup Bible.”“But in order to operate optimally, you need a good night’s sleep. One of the many things that might be keeping you from that is sharing the bed with someone. You just don’t sleep as well when you share a bed.”The Canadian study author Colleen Carney agrees. “People will say they sleep better [together], but when we actually monitor their brains we see that their brain is not getting into deeper stages of sleep because they’re continuously being woken up by movement or sound,” she said in an interview with Canada’s CBC News. “It creates a lot of problems.”As we all know, not getting enough sleep leaves you cranky the next day and not-so-pleasant to be around. A 2013 U.C. Berkeley study found that couples have more frequent and serious fights when they don’t get enough shut-eye. The researchers noted that the lack of shut-eye makes it harder to avoid and handle conflict. “If you’re sacrificing on sleep and you’re tired and grouchy,” noted Sussman, “that’s not going to be good for your relationship or your sex life.”No wonder that sleeping apart is so appealing to some couples. When participants in the FiveThirtyEight survey were asked why they occasionally sleep in separate beds, not surprisingly the top reason (at nearly 46 percent of people surveyed) was snoring, followed by illness and having different sleep schedules. In other words, couples are often making thoughtful choices to sleep solo so as not to disturb their partners. The result: They both have a better shot of nabbing a solid night’s sleep, which sets their day on the right foot.While some might call slumbering in separate beds a “sleep divorce,” Carney advised against making a hasty judgment. “People can have very good and satisfying relationships sleeping apart,” she said. “Some people might be headed to divorce and then they actually sleep apart and find this new way to connect.”Of course, couples who choose to sleep separately still need to make intimacy a priority by slipping under the same set of sheets now and then. “I don’t think there’s anything wrong with your marriage if you sleep in separate beds,” said Sussman, “but you do need cuddle time and sex time, too.”Lots of couples wouldn’t dream of sleeping separately — after all, cuddling is pretty awesome — but we think it’s smart to go your own way at bedtime. If one of you is tossing and turning while the other has a 5a.m. flight the next morning, do what’s best for each other. In those cases, a little space just might bring you closer together.