I did come across this in today's paper though and thought it was an interesting one, I don't know how true it is, however as our results mean our relationship is 91% satisfying I would like to think it's kinda accurate!
Anyway, back to sleep: here are what the common positions say about you:
The full fetal position: Indecisive, anxious and sensitive to criticism
The semi-fetal position with knees drawn up: Open to compromise, unlikely to take extreme action, likely to pacify others
Flat on your back: Confident, open, expansive and thrill-seeking
Face-first: tendency for rigidity and need to be perfect
So there you have it, what does your sleeping position say about you and your relationship?