DOes anyone have any actual proof that s are harmful to a child?

I mean real laboratory reproducable proof. Not biased psycological dogma. Real evidence. Children have been ed for ages, I know a lot of really great people who were ed and they don't have aproblem with it. Why do so many Californians and New Yorkers get their panties in a wad when a child is ed? Remember guys I said ed NOT beaten, there is a differnce to most intelligent people.