I've never seen anyone's bones be broken by a stick or a stone. Maybe a tree and a Boulder...
Anyway-- I agree, words can only hurt you if you really think about the insult and analyze it for days on end. Or if you are just emotionally weak, I know I am, but I still don't let petty insults like "You're fat" or "you're ugly"" get to me because i KNOW that i'm neither of those. You just ave to have a high enough self-confidence to not let the little things get to you. I would almost blame the person being hurt by words more than the person saying them. It's as if the person saying them is giving the kid they're insulting a life lesson, or a test. And seeing if the person passes or not..
And that's my two sense (like the pun there)