I've been indulging in a bit of training with Bridget. Things have come to such a pass that I question my every motive, wondering if such a thing is, by its very nature, oppressive and imperialistic toward the Horse People. Good grief.
Casting doubt aside, I ventured that, as our little Bridget is very clever, it it might be fun to start consciously developing a mutually intelligible vocabulary.
I started the other day. Bridget loves to be scratched. I mean she loooves to be scratched. When she wants me to scratch her hindquarters, she'll rub the whole length of her body against me like a cat and then pointedly push her butt into me. Banking on her natural desire to have me continue scratching, I scratched for a while, then stopped and gently prodded her hip with a finger, asking her to move toward me. The mental gears spun for a second, and then she shifted her quarters in my direction. Scratch, prod again, ditto. We practiced a little on the other side. Today, she instantly moved when I asked her. So I moved up to try it on her shoulders - again, when I asked, there was a pause while the gears meshed, and then she scooted her shoulders toward me, crossing her front legs. Switch to the other side - no pause - this time she knew right away.
This kind of thing is artificial and a little mechanical. The horses tend to gracefully move as need requires in the course of our daily activities together. For example, today as I was leading Chloe on a rope back to the pasture through the gate, she very politely turned back with me toward the gate, without prompting, when I went to close it. The more natural way to develop a mutual understanding is probably through lively interactions of this nature rather by "encoding" rote responses to predetermined stimuli.
But ... we'll try a little of this kind of thing - see what happens - see what we think of it - see what the horses think of it.