Join Date: Dec 2010
Location: southern Arizona
I think horses figure out what their owner means and interpret it accordingly. They are entirely capable of learning a pat from their owner means their owner is relaxed and happy, and they can relax and be happy too. They can learn it means, "Pressure gone, relax for the next 60 seconds". But I think it is a learned reaction to their owner rather than instinctive.
My horses seem to enjoy 20-30 seconds of wither rubs/scratches. I don't pat, so they would be surprised if I started now. I don't think they view rubs as a "reward", but I see no sign they object to them. Head rubs at the end of a ride always seem to be appreciated. I'll hold my fist, and the horse will rub its head against my fist quite hard for 30 seconds or so. Since the horse is doing the rubbing, I have to assume it feels good - at that time. But I've never had a horse keep it up for much over a minute, either.
Riders ask "How?" Horsemen ask "Why?"