1. The Fetus.
It is sleeping sideways, shrunk with the knees towards the chest, arms crossed near the legs. Its name derives from the position of the babies in the maternal womb. It is the most frequent position used by most people. In the study cited above, 41% of the 1,000 participants chose it, women, twice as much as men.
As for the personality, there are several variants. For example, “curling up” to sleep is related to sensitivity and emotional, as well as the tendency for more intense relationships. The person may seem shy when meeting someone, but then relaxes and becomes very warm, loving and fears being hurt sentimental.