Forget sleep divorce; here's why sleeping with your partner is good for your health

Move over sleep divorce, dozing next to your partner is the best nighttime habit you can adopt not only for a better quality rest, but also for overall health benefits. Science shows that couples who share a bed tend to sleep longer, experience better sleep quality, and even sync their heartbeats to each other over time. But there’s a catch: these benefits only apply to emotionally connected partners, not casual flings or one-night stands.
Co-sleeping helps partners enjoy enhanced overall wellbeing, reduced stress, and even synchronized heartbeats. The benefits multiply if the emotional intimacy is higher.
“Sleeping in pairs can enhance physical and emotional security,” Dr. Thomas Michael Kilkenny, director of the Institute of Sleep Medicine at Northwell Staten Island University Hospital, told The New York Post.

“The closer the couples are emotionally, the more synchronized the sleep becomes,” he added.
“Studies using brain waves showed significantly increased sleep durations when co-sleeping,” Kilkenny said. “The subjects also felt significantly more relaxed after having slept with their partner.”

Having sex, cuddling, holding hands and sleeping close can trigger the release of oxytocin, also known as the “love hormone,” which promotes relaxation, reduces stress and creates a sense of security.
A study published in Sleep Science found that the physical and sexual intimacy caused by sleeping next to a partner triggers the release of a hormone known as oxytocin. The hormone not only promotes better sleep, it also reduces stress and promotes bonding.
Oxytocin also contributes to longer sleep time. Increased REM sleep can help in emotional regulation, memory consolidation, brain development and dreaming.

Kilkenny said that research shows that people who sleep with a partner, even if not in the same bed but simply in the same room, experience less fragmented REM sleep compared to sleeping alone. A research published in Frontiers of Psychiatry says, as compared to sleeping individually, co-sleeping was associated with about 10% more REM sleep, less fragmented REM sleep, longer undisturbed REM fragments, and more limb movements.
Kilkenny also discussed a fascinating phenomenon saying the couples who share bed end up synchronizing their sleep stages, which can improve sleep.

Kilkenny compared this occurrence to a phenomenon known as “Huygens synchronization,” according to which two pendulum clocks will eventually swing in rhythm if they are placed near each other because they will subtly influence the other through vibrations.
According to the expert, the couple's mutual attention and the nature of the relationship, like if it’s a romantic couple, close friends or hookup buddies, will impact this synchronisation. Emotional attachment thereby plays a key role in this.
“People who slept in the same bed who were not emotional or socially attached to each other did not demonstrate any of these synchronization patterns,” Kilkenny said.
“Data shows that the heart rhythms of co-sleeping individuals gradually change over the night as a result of the interaction with each other,” Kilkenny said.
Kilkenny says the hearts “talk to each other” as partners sleep, he said, with “the heart rhythm of one co-sleeper acting as an external stimulus that affects the heart rhythm of the other co-sleeper.”