Want a better relationship? Science says it involves sleep.

Great relationships have thrived on less harmony. Separate sleeping arrangements can be a boon for a relationship, and even rocky pairings rely on nighttime spooning so couples can get some zZz’s. But two different studies reveal that sleep may be more important to a relationship than just the 8-hour reboot it’s credited with. While many couples are content sleeping in separate beds, it turns out that there is an association between happy relationships and sharing a bed. According to one study (of heteronormative marriages between men and women), couples sleep better and ‘sync’ sleep schedules when the wife is happier with their marriage. The most satisfied couples woke and slept at the same time—logging over 75 percent of their sleep hours in tandem. When the wife was content in the relationship, both experienced the effects of this consistent sleep pattern together.

That said, I can relate. I seem to sleep better when my husband is around. It may be that I’m simply used to having him there in bed with me. Or perhaps I associate being around him with shutting down for the night. Either way, it’s nice to know that we’ve bonded so closely—even down to our shut-eye. This study encouraged me to create heart-to-heart conversations during the day with my husband, rather than rely on our nighttime routine of chatting before we fall asleep. Maintaining our relationship is important to both of us, and maybe to our sleep too. Whether or not you sleep with a partner, sleep loss can affect your relationships in other ways. Dr. Adrian Williams, professor of sleep medicine in the UK, points out that sleep loss has quite a few effects that might influence relationships including a reduction in self-control as well as moral awareness. It can also foster an inability to interpret mood, particularly sadness. Quality sleep may even help you interpret your partner’s mood more efficiently, which can help communication. Another correlation exists between sleeplessness and analysis of facial expressions; a study found that sleep deprivation may impair your ability to recognize facial expressions. These findings came as no surprise to me. Lacking precious moments of sleep, I’ve been known to respond blankly to family members who need something from me, and I’ve failed to be attentive to a particularly “down” day for one of my kids. I used to think this was a particular brand of sleep-deprived selfishness. Science confirms that sleeplessness messes with your ability to recognize how other people feel. Although I can’t always control my sleep, I can be more mindful about how my quality of sleep is affecting me. [Editor’s Note: if this is an area you’re struggling with, try the Sleep single.] I try to keep this in mind. After one sleepless night, I may misinterpret my husband’s signals. Instead of jumping to conclusions about his motives or feelings, I’m working to give him the benefit of the doubt when I’m overtired. If I’m really not up for it, we may need to shelve an important discussion for a day when we’re both well-rested. Williams cautions against putting too much stock in sleep messing with your inability to analyze moods, however. While he agrees that sleep deprivation results in a reduction in the ability to recognize subtle changes in facial cues, Williams points out that this occurs “after almost 24 hours of no sleep and applies mainly to sadness, with smaller effects regarding happiness.” However, I would argue that adding a little extra patience to your responses after too little sleep can only be a good thing.

The wife in the relationship proved to be the key factor. According to Science Daily, “When the wife reported higher marital satisfaction, the percent of time the couple was awake or asleep at the same time was greater.” In other words, high marital satisfaction (at least, for the wife) was correlated with syncing sleep. The study did not include relationships outside of this heteronormative structure, so more research needs to be done. That said, I can relate. I seem to sleep better when my husband is around. It may be that I’m simply used to having him there in bed with me. Or perhaps I associate being around him with shutting down for the night. Either way, it’s nice to know that we’ve bonded so closely—even down to our shut-eye. This study encouraged me to create heart-to-heart conversations during the day with my husband, rather than rely on our nighttime routine of chatting before we fall asleep. Maintaining our relationship is important to both of us, and maybe to our sleep too. Whether or not you sleep with a partner, sleep loss can affect your relationships in other ways. Dr. Adrian Williams, professor of sleep medicine in the UK, points out that sleep loss has quite a few effects that might influence relationships including a reduction in self-control as well as moral awareness. It can also foster an inability to interpret mood, particularly sadness. Quality sleep may even help you interpret your partner’s mood more efficiently, which can help communication. Another correlation exists between sleeplessness and analysis of facial expressions; a study found that sleep deprivation may impair your ability to recognize facial expressions.

These findings came as no surprise to me. Lacking precious moments of sleep, I’ve been known to respond blankly to family members who need something from me, and I’ve failed to be attentive to a particularly “down” day for one of my kids. I used to think this was a particular brand of sleep-deprived selfishness. Science confirms that sleeplessness messes with your ability to recognize how other people feel. Although I can’t always control my sleep, I can be more mindful about how my quality of sleep is affecting me. [Editor’s Note: if this is an area you’re struggling with, try the Sleep single.] I try to keep this in mind. After one sleepless night, I may misinterpret my husband’s signals. Instead of jumping to conclusions about his motives or feelings, I’m working to give him the benefit of the doubt when I’m overtired. If I’m really not up for it, we may need to shelve an important discussion for a day when we’re both well-rested. Williams cautions against putting too much stock in sleep messing with your inability to analyze moods, however. While he agrees that sleep deprivation results in a reduction in the ability to recognize subtle changes in facial cues, Williams points out that this occurs “after almost 24 hours of no sleep and applies mainly to sadness, with smaller effects regarding happiness.” However, I would argue that adding a little extra patience to your responses after too little sleep can only be a good thing.

Need a little Zen in your relationship? Try this.

One of my favorite coffee mugs looks like a measuring cup: the first line at the top admonishes: “Shhh,” then “Almost,” for when you’re half-way finished. “Now You May Speak,” is reserved for when you’re down to the dregs of that familiar liquid gold. My kids know that I’m in a better mood once I’ve ‘woken’ up with a cup of coffee. When I’ve had a bad night’s sleep, I reach for a cup of joe. But while it’s not clear whether coffee can help you navigate relationships better, it is clear that some good shut-eye might do wonders.