Negative reinforcement is where an animal is subjected to an aversive that it dislikes enough that it will work to avoid that aversive. Only when the animal has performed the task you require will the aversive cease. The stronger the will of the animal, the harsher the aversive will need to be in order to make the animal work to avoid the aversive, rather than fight against you.
This is the method of choice for the majority of horse trainers and there is a term used to describe the process of taming a wild horse using this method. It is called BREAKING a horse. Breaking his spirit to be more precise. Removing his spark for life until he has no fight left, no free will.
Only then will the horse meekly accept future negative reinforcement with no fight. A broken horse will accept every whip, every jerk of the reigns and every kick of the stirrup.
Is that what we want from our dogs? Broken spirits. No lust for life. I for one want a dog that is as confident as he can be. I want a dog that feels free to try new things in the ever changing operational environment, without fear of being lashed. When I shout I want my dog to look around to see who I am shouting at and join in by barking not cower by my side, fearful of being hit.
Positive reinforcement training produces confident, willing dogs. Negative reinforcement, which carries with it all the negative side effects of punishment such as stress and displacement activity, produces the exact opposite. Wild horses couldn’t make me choose negative reinforcement as my training tool of choice.