It is an odd thing, but it seems that sleeping preference is a "learned behavior." In that, most I can find is on infant sleeping position. There is a lot of research and discussion on this because prone--"on tummy"--is considered a risk factor for SIDS [Sudden Infant Death Syndrome.--Ed.] Anyways:
Quote:
Positional preference appears to be a learned behavior among infants from birth to 4 to 6 months of age. The infant, being placed in a back or side position in the newborn nursery, will become accustomed to this position.
Infant Sleeping Position and SIDSNow no one--unless they have a spinal cord injury--remains in the same sleep position. We move. Of course, we do that while we are asleep. Some more searching and there is this interesting article:
Quote:
High correlation was found when comparing subjects’ self report of their common sleep positions with the video record. The sensitivity of self reported ‘usual’ night side lying sleep position was 89% and ‘last’ night reports 95%. Sleep position was consistent across repeated nights’ sleep, and there was good reliability between subjects’ self report of ‘usual’ (92%) and ‘last night’ (83%) sleep positions.
This study reports high validity, reliability and consistency in self reports of ‘usual’ and ‘recent’ sleep positions.
. . . .
People first begin to develop a definite sleep position, at about three months of age, when infants begin to move freely and turn over by themselves, by the age of seven years a definitive sleep position is assumed. In adults the most common reported sleep position is the semi-foetal position, with other common positions being full-foetal, prone and supine. Although individuals have a pattern of constancy with regard to sleep position 9 as age increases this pattern changes with increased preference for the side sleep position, decreased preference for the prone sleep position, decreased position shifts and increased amounts of postural immobility 10 lasting between 45 and 110 minutes.
Self Reported versus Recorded Sleep PositionHowever, this chair seems oddly . . . familiar:
"Be seeing you!"
--J. "UNMUTUAL!" D.