The weight seems to be beneficial for people with Aspergers and Autism. But I knew from having slept under weight myself, while staying with my grandmother as a child and sleeping under heavy comforters that there is something comforting about it. I also used to own a heavy feather pillow, an ancient pillow, that I would place over my head at night to block out sounds. I loved that pillow, but I could also hear vermin crawling in it...I'm not kiddin'. I plan to make my own weighted pillow from the poly beads.
Sounds crazy, eh!