You keep shifting your goalpost and ignoring like half of what I say in each comment. Now suddenly early horses were chosen because they're so much smarter than zebras and donkeys. Did you ever think that maybe horses have been bred for their intelligence? They're also nearly half a meter taller now too, because we bred them for it. Did you personally compare the intelligence of early horses to zebras? Hell, even to Przewalski's horse, if you want to get comparative about it. Because if not, you have no point here, just more guesses.

We're back to child cavalry now, are we? What exactly can you get done more with a child on the back of a horse that you couldn't get done by just having the horse pull something? Bear in mind, that in order to tame a horse for riding so that it won't buck you off, you need someone to break it in while on its back, a back that won't hold an adult; even modern horses don't like this process when feral and they've been bred for this for thousands of years. So now you need tweens breaking them in. So you're arguing that a culture decided to have their children try to be the first horsemen, something that's incredibly dangerous and at that point hadn't been tried; and for what reason, you still haven't said. Not to mention, there is exactly zero evidence for child-only horsemanship in either history or archaeology; but hey, it makes you think you're clever.

I guess all of history, anthropology, and archeology are wrong, though, and some dude on the internet is right. You got me. Go ahead and respond in whatever way makes you feel smartest if you really feel like you need the last word. I won't be reading it.