An aversive stimulus is, by definition, something an animal will work to avoid. Trainers who consider themselves “positive” generally try to omit aversive stimuli from their work with dogs. In dog training there are no mystical forces; the dog is either working to gain access to an appetitive stimulus (meat, cheese, tennis ball, latex squeaky things, etc.) or he is working to avoid an aversive stimulus (pressure on the collar, spray of water, shake of penny can, etc.). This is not a new concept, but there is an aversive stimulus that we all need to pay more attention to. It has crept into too many of our training sessions, and you’ve probably experienced its insidious effects. The stimulus is confusion.

Confusion: the state of being bewildered or unclear in one’s mind
There are a few common questions that land in my inbox that almost certainly point to this toxic culprit.
“My dog quits during training. How do I get my dog more resilient to failure?”
May I shout it from the rooftops once and for all? Failure is a human construct; dogs have no concept of it. When you say “failure” in reference to training you are referring to non-reinforceable repetitions. That means that when you seek resilience in the face of failure what you’re really after is a dog that keeps trying though he isn’t being paid. Sadly the idea that a dog should try, try again, though his trainer is doing nothing to help him and he is not receiving reinforcement is pervasive in the sport of dog agility. What’s amazing about dogs is that so long as they understand how to get reinforcement, they often will keep trying, even if their trainers are being unfair. The dogs that are labeled “quitters” or “not resilient to failure” are often just confused. Dogs that walk away from training sessions where reinforcers are available are experiencing an aversive stimulus strong enough to make the potential for reinforcement irrelevant. That stimulus is usually confusion. If you find that your dog starts strong in shaping sessions but eventually “quits,” it’s time to examine your mechanics, your splitting, and your overall plan. Your dog’s not a quitter; he’s a product of his training. And he’d like very much to not be confused.
“Why does my dog shut down in agility trials?”
If your dog “shuts down” in agility (particularly in trials, where no classic reinforcers are available) it is wise to consider two things: training and handling. If you have a dog you refer to as a “shut down” type, look yourself in the mirror and ask, “Have I adequately trained this dog to perform this task?” and “Have I adequately prepared myself to direct my dog on course in a clear and consistent way?”
To be fair, we all make mistakes both in training and in handling our agility dogs. It is when confusion becomes what the dog expects that we see the troubling set of behaviors we refer to as a dog “shutting down.” Confusion, just like any other aversive stimulus, can act to make our favorite dog game a conditioned punisher. When our dogs experience the “walk into the ring, experience confusion” scenario often enough, that ring begins to hold the same overall feeling of yuck that the confusion does.
So what do we do? What if we have allowed confusion to poison our training or our sport?
Abandon Falsehoods
There are a lot of falsehoods in dog training, and agility holds its own special mythology. That our dogs must be resilient to failure, that they must work through frustration, that they should experience disappointment and confusion in training in order to withstand these things in life, are just some such fables. Abandon them. Walk away from the folklore you’ve been told and toward the science-based training world. You’ll be so glad you did.

Ghost’s bright expression and speedy performance tell us she is clear about what she is doing
Get Real About Skills
All of us started out kind of crappy at training, and most of us didn’t learn to stay upright on course overnight. Being a better trainer and handler isn’t about age, hours in the week, physical capability, or the dogs next to us. Improving skills is about deciding to be better. It’s about seeking out teachers that help us reach our goals, judgement-free. It’s knowing what we don’t know, and deciding to find the answers. There is a world of information available to us all if we only choose to seek it out. Your dog is worth it, even if you think you aren’t.
Be a Little Kinder
No one learns while someone is being mean to them. Guess what? That applies to ourselves. Getting down on yourself because your dog’s issues are your fault won’t help you or Fluffy to improve. So as you go to your new coach and you take that online clicker training course and you work to better your skills for the dog you love don’t forget to pat yourself on the back. It takes a big person to go back to school.