Despite Disturbing Each Other’s Sleep, Mice Refuse Sleep Divorces

This study appears to reinforce what many humans have already learned through experience: Sleeping with a partner can cause sleep disruptions, Trusted Source American Academy of Sleep Medicine (AASM) AASM sets standards and promotes excellence in sleep medicine health care, education, and research. View Source but sleeping away from a partner can feel lonely. Therein lies the dilemma: should you continue to share a bed despite sleep disruptions or file full steam ahead for sleep divorce? 

A sleep divorce refers to the practice of sleeping in a different room from your partner. People who try sleep divorces often do so to avoid having their sleep disrupted. Celebrities like Cameron Diaz and Carson Daly have endorsed the practice. But, a January 2023 SleepFoundation.org survey found that over 25% of people who try a sleep divorce end up sleeping together again. Of these, 35% say they reunited because they missed each other. Much smaller percentages cited other reasons, such as resolution to relationship issues, a change in work schedules, or their sleep quality was worse when they slept apart. 

The University of Michigan research team coined the term “somatolonging” to describe the desire to remain in physical contact with another for an extended period. Because of this desire, the mice prioritized cuddling together over sleeping in their preferred locations. They stayed together even when it disrupted their sleep. 

Researchers uncovered the mice’s preference for cuddling by first monitoring a mouse’s behavior in a “home” environment or a place it was accustomed to sleeping. Then, they introduced one or two other siblings or familiar mice sleeping in a nest that the first mouse did not consider home. When it wanted to rest, the first mouse would sleep in the place it didn’t prefer, just to be close to the other mice. Researchers monitored the mice using video recordings and wireless devices Trusted Source University of Michigan Medicine Michigan Medicine is the site of many groundbreaking medical and technological advancements since the Medical School first opened in 1850. View Source and then evaluated the data to classify their behavior. 

Mice who slept near familiar mice experienced coordinated sleep, meaning they were more likely to fall asleep, wake up, and go through various sleep cycles at the same time as the mice they cuddled with. Researchers posit that a feeling of safety may be the reason sleep patterns coordinate.

Although mice behavior doesn’t always reflect human behavior, humans can also experience somatolonging, according to Ada Eban-Rothschild, Ph.D., one of the study’s authors and assistant professor at the University of Michigan. This could explain why a sleep divorce isn’t for everyone. The innate desire for physical touch may outweigh some people’s desire for better sleep. 

A January 2024 SleepFoundation.org survey found that among couples in which one person snores, 56% continue to sleep in the same room. More than one-third of them do so because they’d rather sleep near their partner than apart, even if the snoring wakes them up.

So if you choose to cuddle with a partner despite them waking you up at night, know that you aren’t alone.