Sleep specialist, Dr. Neil Stanley, told the British Science Festival how bed sharing can cause rows over snoring and duvet-hogging, and thus rob a couple of precious sleep.
One study found that, on average, couples suffered 50% more sleep disturbances if they shared a bed.
Dr. Stanley, who sleeps separately from his wife, points out that historically people were never meant to share beds. He says the modern tradition of the marital bed only began with the industrial revolution, when people moving to overcrowded towns and cities found themselves short of living space.
"If you've been sleeping together and you both sleep perfectly well, then don't change, but don't be afraid to do something different," Dr. Neil Stanley advises. Before the Victorian era, it was not uncommon for married couples to sleep apart. In ancient Rome, the marital bed was a place for sexual congress but not for sleeping, the expert explains.
Dr. Stanley, who set up one of Britain's leading sleep laboratories at the University of Surrey, said couples don't have to sleep in the same bed even when it is clearly uncomfortable.
"It's about what makes you happy. If you've been sleeping together and you both sleep perfectly well, then don't change, but don't be afraid to do something different.
"We all know what it's like to have a cuddle and then say 'I'm going to sleep now' and go to the opposite side of the bed. So why not just toddle off down the landing?"
He said poor sleep has been linked to depression, heart disease, strokes, lung disorders, traffic and industrial accidents, and divorce, yet sleep was largely ignored as an important aspect of health.
Dr. Robert Meadows, a sociologist at the University of Surrey, said: "People actually feel that they sleep better when they are with a partner, but the evidence suggests otherwise."
He carried out a study to compare how well couples slept when they shared a bed versus sleeping separately.
Based on 40 couples, he found that when couples share a bed and one of them moves in his or her sleep, there is a 50% chance that their slumbering partner will be disturbed as a result. Despite this, couples are reluctant to sleep apart, with only 8% of those in their 40s and 50s sleeping in separate rooms, the British Science Festival heard.