The Effect of Flies on Horse Behavior

In the early 1900s, a doctor or sorts who was studying human behavior in general realized that he had found this horse that could count. And they realized that the horse was detecting little subconscious, nuanced body language with people around. It was almost proof of how smart they were, but it was taken to be a proof that they weren't smart at all. "It just hurts my soul to think about horses just being kept in the little boxes staring at blank walls"