Sleeping together with your partner is not just about sex or how much of the blanket and quilt you hog on the bed; it can be a silent signal of your satisfaction with your bed partner. Our body language when we sleep and the specific sleep positions we take when sharing a bed, can be an indicator of our health and our relationship. According to a study published at the Edinburgh International Science Festival, the closeness of a couple and how happy they are in their relationship is reflected in the distance they keep between themselves as they sleep.

"This is the first survey to examine couples' sleeping positions, and the results allow people to gain an insight into someone's personality and relationship by simply asking them about their favorite sleeping position," said Richard Wiseman, lead author of the study, and psychology professor at the University of Hertfordshire, according to Science Daily. Wiseman’s research expands on the work by psychiatrist Samuel Dunkell, author of "Good-bye Insomnia, Hello Sleep,” who has analyzed the body language of sleep for more than 25 years. Dunkell has previously decoded the sleeping styles of individuals, such as finding people who sleep in the “semi-fetal” position — with their knees drawn up — are peacemaking, willing to compromise, and less likely to take extreme stances, and people who sleep in the “royal position" — flat on their back — tend to be confident, open, expansive, and sensation-seeking.

Wiseman’s study, conducted as part of the Edinburgh International Science Festival, sought to reveal how it is possible to tell how happy a couple is together by measuring the distance between them as they sleep. Over 1,000 people filled out a survey that asked them to describe their preferred sleeping position and to rate their personality and quality of their relationship. The study also examined the difference in sleeping styles among extroverts in the sample size.

The findings revealed the most popular sleep positions for surveyed couples: 42 percent slept back-to-back, 31 percent slept facing the same direction, and just four percent spent the night facing one another. In regard to distance, 12 percent of couples spent the night less than an inch apart, while two percent of the survey respondents spent over 30 inches apart. Overall, the farther apart the couples spent the night, the worse their relationship fared. Of those who slept less than an inch apart, 86 percent reported being happy with their partner, compared to only 66 percent of those who slept more than 30 inches apart. When it came to extroverts, out-going extroverts were more likely to spend the night close to their partners, while more creative individuals tended to sleep on their left-hand side.

Touching during sleep was also found to be a significant indicator of relationship quality among couples. “One of the most important differences involved touching, with 94% of couples who spent the night in contact with one another were happy with their relationship, compared to just 68% of those that didn't touch,” said Wiseman, according to Science Daily. Those in the happiest relationships slept face-to-face while touching, and even if couples had different sleep positions but made physical contact at night, they were happier than those who did not touch.

Although sleep positions could be a silent indicator of trouble, sleep habits are individualized and should be taken with a grain of salt. A couple’s sleeping style could be due to contributing factors such as a partner’s snoring, which could influence how close couples decide to sleep next to each other. Also, some couples express the need to face away from their partner because they cannot tolerate someone breathing on them. However, red flags should go up if one partner does not want to have physical contact, especially when they both enjoyed touching when sleeping.

“The key issue is if you have a couple who used to sleep close together but are now drifting further apart in bed, then that could symptomatic of them growing apart when they are awake,” Wisemam said, The Telegraph reported. "Change in a couple's sleeping habits is the important factor."

Source: Wiseman R. Research reveals what your sleeping position says about your relationship. University of Hertfordshire. 2014.