A new study suggests that couples are more likely to sleep in sync when the wife is more satisfied with their marriage.

Results show that overall synchrony in sleep-wake schedules among couples was high, as those who slept in the same bed were awake or asleep at the same time about 75% of the time. Self-reported relationship satisfaction by wives was not associated with couples’ overall daily rhythmicity but did predict couples’ sleep-wake concordance. When the wife reported higher marital satisfaction, the percent of time the couple was awake or asleep at the same time was greater.

“Most of what is known about sleep comes from studying it at the individual level; however, for most adults, sleep is a shared behavior between bed partners,” says lead author Heather Gunn, PhD, postdoctoral scholar at the University of Pittsburgh, in a release. “How couples sleep together also may be influenced by their relationship functioning.”

The research abstract was published recently in an online supplement of the journal Sleep and was presented yesterday at SLEEP 2014.

The study group comprised 46 couples who completed relationship assessments and a daily five-item Social Rhythm Metric (SRM) over a 10-day period. Objective sleep and activity data also were gathered by actigraphy throughout the study period.

“The sleep of married couples is more in sync on a minute-by-minute basis than the sleep of random individuals,” Gunn says. “This suggests that our sleep patterns are regulated not only by when we sleep, but also by with whom we sleep.”

The study was led by Wendy M. Troxel, PhD, behavioral and social scientist at the RAND Corporation and an adjunct professor of psychiatry and psychology at the University of Pittsburgh. Research funding was provided by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH).