http://www.gaitedhorses.net/Articles/ATD10.shtml
If you read this article, you can understand the horses better. As a human, you know all about human body language, so you can understand why Joe does what he does. But, as you are not a horse, you may not understand why Star and Sungwiye do what they do. When you do understand, it adds another aspect to the book, and two more characters. Also, after reading the human-and-horse-communication section, the reader will understand why Joe does certain things when he is with Star.
My personal reaction to the article is amazement. I was shocked to see that a little involuntary action can upset a horse. Even eye contact can be viewed as a challenge, or cause the horse stress! Also, you learn how to tell when a horse is thinking, or paying attention to something. If you take horseback riding lessons, your instructor will tell you to tuck in your bottom, and to squeeze, not pull the reins. This is echoed in the article, but it gives a reason to do that. Tucking your bottom encourages the horse to do the same, therefore slowing it down, and stopping.
