Commenter cranky-d writes:

That sounds like the kind of horse I would like to have.  I have tried riding and like it some, but I tended to end up with horses that wanted to screw with me, and the instructor was unhelpful.

It’s a matter of psychology. As I said, I’m no rider, but I do pretty well on the ground. I’ve been a technologist all my life; the most astonishing discovery I have ever made about myself was not that I’m a good horse trainer — I’m not — but that I’m not a hopeless one.

Horses are herbivores, prey animals, and herd animals. When approaching them you have to walk a somewhat fine line: you must not induce them to see you as a predator or potential predator, but you have to firmly establish that you are higher up than they are in the pecking order. Providing or withholding food is one way to do that, but it is absolutely essential to show neither fear nor aggression. If you show fear you’re just one of the herd, and the horse will try to establish itself as senior to you. If you show aggression, the horse will conclude that you’re a predator and either try to stomp you flat or run away.

As a result, horse-management is a definitional example of the cynical concept of “command decision”: it is better to be sure of yourself and wrong than it is to be tentative. A person who approaches a horse in a diffident, tentative manner, unsure of him- or herself in the new situation, finds that the horse engages in all kinds of avoidance behaviors to keep from doing as the rider or trainer wants. A horse that encounters a human who approaches it confidently and without hesitation, but without behavior that could be seen as aggressive, is a happy horse who is glad to see that someone who knows what he/she is about is in charge, and turns its mind to figuring out and accomplishing what is wanted. From there it is only necessary to communicate to the horse what is wanted — and that’s difficult; horses have very limited communications skills.

This, by the way, is the reason children — especially prepubescent girls — can sneak into the paddock, climb bareback onto the most fractious nag there or for five counties ’round, and get exactly what they want rather than trampled. They approach without real fear, and with that absolute certainty that what they want is a Law of the Universe so characteristic of that age group; the horse’s reaction is ooh, so nice, let’s have fun! and off they go. I was visiting a friend one day, and we heard noises from the paddock. When we investigated, we found his neighbor’s ten-year-old daughter and her school friend aboard a rangy, saw-backed bronc famous for bucking, sidling, biting, kicking, and being manageable only by the most-skilled rider, being carried with the care and consideration you wish the movers would give your delicate china. It’s not unusual, and it isn’t an accident.

New (adult) riders and horse-managers often, in fact almost always, have a problem. It is, after all, a completely new skill they are trying to acquire, the horse weighs ten times what they do, and it’s a long way to the ground; they are virtually certain to be diffident and hesitant about applying control inputs and disciplinary measures. In that situation even a school “hack”, accustomed to multiple different riders with different personalities, will sidle away, refuse to go, lunge uncontrollably, turn its head around (and possibly try to bite), toss its head, or (very commonly) simply decide to ignore its rider and do as it pleases.

No, you shouldn’t “saw” the reins, i.e., pull them back and forth — but it is much better to saw the reins with confidence than to apply proper technique diffidently. Yes, the reins should be loose rather than pulled tightly toward you — but if you aren’t alert and ready at any and all moments to let the horse know you’re still there and know what’s going on, the critter will take advantage.

There is a vital, if difficult to apprehend, difference between sure of yourself and knowing the language. Wrong control inputs applied with sure confidence will confuse the horse, but its reaction will be I don’t know what’s wanted here rather than what’s this fool up to? The answer to the first is try again; there may not be an answer to the second other than start over.

Very important: horses don’t think. You are sharing instinct, perception of the immediate, and the sensual pleasure of muscle-on-muscle as applied to distance and the wind with one of the most delightful critters on the planet; your intellect is only applicable to deciding what to do next, and the horse is grateful for it, lacking that ability almost entirely. Approach with your head up and back straight, but without tension; speak firmly but without aggression, sure in your own mind that you are instructing, not begging; sit loosely but with confidence; move fluidly, without jerks or sudden changes, but never tentatively or diffidently; learn the control inputs for that horse (there are several different styles) and apply them as if you know what you’re doing, even if you don’t; and the time becomes pure pleasure for yourself and the horse both.