Robert Phipps, UK's leading body language expert in a survey has identified four basic sleeping positions and said the foetal is by far the most common.
Almost 58 per cent in UK adopt the foetal position and sleep with knees up and head down. The position is favoured by people who worry too much.
"The more we curl up, the more comfort we're seeking," Phipps said.
The second most common position is the log with 28 per cent Britons favouring it, the Daily Mail reported.
A straight body, with arms and legs by the side, apparently indicates stubbornness and they can wake up stiffer than when they went to sleep, Phipps said.
Around 25 per cent prefer the yearner position