[QUOTE=luvmydutch;5015772]
Have you not heard the old saying “you can pat a man and you can pat a dog, but women and horses you stroke”. Do YOU enjoy it when someone comes up behind you and slaps you on the back really hard? That isn’t a reward at all, release of pressure is the only true form of reward in horse training.[/QUOTE]
Except that the right kind of slap on the back can really feel quite good. (And be highly effective if you have chest congestion, added bonus!)
I think we need to specify a difference between hard ‘stinging’ slaps out of the blue and a ‘slap’ with a relaxed/cupped hand that’s more of a ‘thud’ type impact that the horse is reasonably expecting. The former - most horses are either going to tense up or learn to ignore it. The latter - some horses will quite possibly actually enjoy it, some won’t, depending on the individual horse. (Just like dogs and people sometimes prefer different types of touch.)
That said, I think any kind of touch/rub is likely to function mainly as a secondary reinforcement - i.e. something where much of the meaning comes with being associated with a primary reinforcement. (Like if you say ‘good boy’ and give a treat regularly, eventually ‘good boy’ becomes associated with ‘yay, tasty treat coming’ feelings and so ‘good boy’ on it’s own is a reward. Though if you then never repeat the combination of ‘good boy’ and treat then ‘good boy’ can lose value over time.)
So in this case - slap/pat/rub is paired with loose reins and possibly the end of a training session initially, which ‘loads’ it with good feelings for the horse, so then when it’s given in a competition situation where the routine might be different and the horse can’t immediately go back to the barn or whatever, it still functions as a positive gesture.