Do they really make that association? Or is this our projection? This is how you, and many others explain it - but this isn't necessarily what actually goes on. Rather than ascribing a hierarchical nature to a species, we can also see it all in terms of beings establishing hierarchical relationships as such. If a human would be sheepish enough, the horses would dominate the human. This readily happens to dog owners. I don't think this has much to do with horses as such, but rather with the nature of the relationship. So do dogs. And other humans. And other animals. Look, I don't doubt that in human terms, you are good with horses. But I question the very basis of domesticating animals as such, and I question the way people usually talk about their relationships with animals and animal psychology. I grew up on a farm, and have had animals my whole life. But the language that people usually use when they talk about the psychology of animals, is foreign to me. I've always relied on intuition in this regard, and I can't remember a time when it was wrong.