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.