It’s an argument many couples encounter at bedtime, but when it comes to deciding which side of the bed to sleep on, it's women who call the shots, a new study reveals.

The research, led by psychologist, Donna Dawson, found that women insist on sleeping on a particular side of the bed each night and usually get their way as only one in ten men care what side they snooze on.

So is this proof that it's women who wear the (pyjama) trousers in the bedroom? Not according to Dawson who suggests that the man allowing his partner to have her way could be his way of subconsciously protecting her.

“Men are naturally designed to want to protect their female partner and that means, more often than not, they will allow her to call the shots over ‘disputed territories’ like preference for a certain side of the bed,” she told the Express.

“Women are far more likely to insist on things going their way than a man too. Men are generally happy to adapt,” she added.

So why do women have a strong preference when it comes to sharing a bed? According to the findings, it ranges from avoiding their partner’s breath, to wanting them nearer the door to fight off potential burglars.

“There are lots of reasons why a woman prefers a certain side of the bed – being furthest from the door and danger; being closest to the door so she can deal with a crying baby; wanting to be nearer the window for fresher air,” Donna concluded.

“The underlying message is women wear the trousers in the bedroom and men generally don’t put up much of a fight when it comes to bedroom-related disputes.”