I know someone who I can say pretty much whatever I want to, and she won't really be offended. She may say a few words of disapproval, but she won't really get angry.

On the other hand, if I raise my voice a little, it doesn't even matter if what I'm saying isn't really that offensive. She'll immediately get upset, and she'll remain upset for the next few hours.

So, apparently, her brain doesn't really care about the words it should be processing. Mainly what it seems to care about is the raw, dumb, animal emotion. A cliche comes to mind: it's not what you say but how you say it.

I think I'm "human", and I've always thought the people around me were "human" too, because they look like me and mostly act like me, but sometimes I think those other people who look human are actually just dumb animals whose bodies have evolved without their brains following suit.