The apparent success of punishment can be convincing. Punishing will often result in an end to a behavior. It may also result in the temporary suppression of a behavior. At least, as long as the one doling out the punishment is present. Dog pees on the floor, and his owner rubs his nose in it. Next time the dog needs to pee he slips behind the couch.
Dog growls or shows aggression. Punishment happens. Dog no longer shows signs of aggression. But is the underlying emotional cause gone? Absolutely not! Punishment of these warning signs often leads to dogs that bite “without warning”. We humans, in our infinite wisdom, are notorious for punishing out the warnings our dogs give prior to biting. It doesn’t change the anxiety that leads to the aggression, it just changes the dog’s decision to warn us about our transgressions.
Aggression begets aggression. That is a fact, and it often occurs on both sides of the equation. We punish something we don’t like, get a result, and next time it happens we punish again, often with harsher punishment than before. We feel a sense of satisfaction from the suppression of the unwanted behavior. Because of this we are rewarded for punishing. Basic behaviorism tells us that any behavior that is reinforced will grow stronger. It is a hard pill to swallow, but it happens all the time when we use punishment.
Aggression also can lead to more aggression from our dogs. Because we are now perceived as a threat to them because of our perceived erratic and violent behavior, they must defend themselves. If we set up an adversarial relationship with them we should not be surprised when that is what we end up with.