I think what we have here is brain damage. Damage to that part of the brain that has evolved culturally over the past 10,000 yrs. That is, since the agrarian revolution. That's why we have so many causes, i.e. pollution, developmental defects etc. That's not to say that all evolution is a good thing. It just is positive for the culture. Its really not good or bad . It just is. I don't think it has anything to do with intelligence but rather how the culture measures it. The part of the brain that this evolutionary development occupies is located in the same area of the brain that deals with movement stimulus. The movement becomes a pacifier in some cases for the recipient. That's why there are so many causes and no cures. The only real cure is to learn to live with it or wait until the culture goes back to hunting and gathering. Any comments?