Have you SEEN half the replies in here? They're all along the lines of "Just don't touch anyone ever again!"
That....that kind of is "omg we can't hug anyone anymore ever again!"
Also, you really frown on the word hysteria lol. I admit it's not psychologically founded - it's a....it straddles the line of sociology (which is barely a real science!). But I can at least give you a PARTIAL foundation: Briquet's syndrome. It's a mental disorder characterized by phantom somatic symptoms. Like.....pain or sensations that aren't really there, but AREN'T the result of physiological problems (like a brain tumor creating phantom smells). You can think of it like a very twitchy nervous system. Now, Briquet's is, kind of cool actually, contagious! Ever seen someone that really, REALLY badly hurt their knee? Your knee kind of tingles, right? Well, with a case of Briquet's, the pain is almost replicated: Seeing someone hurt hurts YOU! Now, it's been on and off the DSM every time there's a new version because it's really, REALLY rampant and it's really difficult to gauge reactions and sensations. But the neat thing is? Briquet's affects the somatic nervous system, which in turn causes the pineal gland of the brain to light up.
Guess which part of the brain lights up when hysteria is induced? :)
Granted, this is all.....REALLY rough and barely a science lol. In my opinion it needs serious exploration, but the similarity is interesting, right?