"Aversives": A little something for the newer trainer.
In psychology, aversives are unpleasant stimuli that induce changes in behavior through punishment; by applying an aversive immediately following a behavior, the likelihood of the behavior occurring in the future is reduced. That is mostly true in dog training, but a significant exception is forcing, during which a behavior is made more likely to reoccur through the application of an aversive stimulus. Aversives can vary from being slightly unpleasant or irritating (such as a disliked color) to physically damaging (like a 2x4!). It is not the level of unpleasantness, but rather the effectiveness the unpleasant event has on changing behavior that defines the aversive. Aversive tools apply ‘unpleasant stimuli’.
The above description includes the word ‘punishment’. But that isn't specifically accurate in all dog training applications. I’m not going to launch into an Operant Conditioning discussion (yet). But what we’re really talking about here are aversive tools. Ear pinch, heeling sticks, e-collars, et al. They may punish, correct, or merely compel. But they do so by being used as implements that apply unpleasant stimuli (pressure/force).
I thought this might be a worthy discussion, what with hunting season coming up and all! I don't know about you, but I'm sharpening my dog up for hunting! :)