Do People Sleep Better With A Partner? This Small Study Suggests Yes 

A good night's sleep is critical for a person's health, mood, and overall energy the next day. There are several methods for achieving a good night's sleep, like establishing a nightly routine, taking a supplement, or listening to white noise. And according to a small study, published in the journal Frontiers in Psychiatry, falling asleep next to a romantic partner may also help. 

The researchers analyzed sleep patterns of 12 heterosexual couples—both individually and together—over the course of four nights. Using a method called dual simultaneous polysomnography, they measured brain waves, respiration, muscle tension, bodily movements, and heart activity throughout sleep. The couples also answered questionnaires about their relationship status, including levels of passion and depth, as well as the length of the relationship.  

They found that couples who slept together experienced an increase in rapid eye movement (REM) sleep, which is thought to be connected to dreams, emotions, memory, and creativity1.

Additionally, couples who scored highly on "relationship depth" were more likely to synchronize their sleep movements. Interestingly, even when couples physically moved around, their sleep quality was not disrupted.

Past studies on couples' sleep quality have actually found opposite conclusions. A 2016 study, for example, found that couples who sleep in the same bed experience a decrease in sleep quality and an increase in mental health issues2. Other studies have gone so far as to say that sleeping in separate homes, or "living apart together," can improve the outcome of a couple's relationship. 

One reason for the differences may have to do with methodology, Drews suggests. Many of those studies infer sleep quality based on a measurement of bodily movements, called actigraphy, he explains. 

"Since our study also measures brain waves (EEG), we can clearly see that the movements—which are indeed increased when sleeping with a partner—do not actually disturb sleep," Drews says. "One could say that while your body is a bit unrulier when sleeping with somebody, your brain is not. And that is what counts."