Couples are more likely to sleep in sync when the wife is more satisfied with their marriage, a new study has found.
Researchers found 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 per cent of the time.
When the wife reported higher marital satisfaction, the per cent 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 behaviour between bed partners," said lead author Heather Gunn, postdoctoral scholar at the University of Pittsburgh.
"How couples sleep together may influence and be influenced by their relationship functioning," Gunn said.
The study group comprised 46 couples who completed relationship assessments. Objective sleep data also were gathered by actigraphy over a 10-day period.
"The sleep of married couples is more in sync on a minute-by-minute basis than the sleep of random individuals," said Gunn.
"This suggests that our sleep patterns are regulated not only by when we sleep, but also by with whom we sleep," Gunn said.
The research was published in the journal Sleep and presented at SLEEP 2014, the annual meeting of the Associated Professional Sleep Societies LLC in Minneapolis, Minnesota.