Sleeping in separate beds sounds like what Grandma and Grandpa did to maintain modesty, 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 ofThe 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.