Ow

So yesterday, after finding myself saying "ow" 'cause of my back hurting, I got to wondering where the word comes from and why people say it.

I mean, people now just assume that you say Ow when you're in pain, it's just the norm. But really why do we do it? I really don't think it's natural instinct to say it. My idea is that we're all raised seeing that it's what's said when you're in pain, so we just start doing it ourselves and following by the example set for us.

Sadly, my google-fu isn't good enough to find a more substantial answer to this other than my theories.

It makes me wonder though...I think when I have a kid, instead of saying "ow" when something hurts, I'll start saying the word elephant. Then I can see if the kid says elephant for the rest of their life when they get hurt...