I believe B. F. Skinner was the first person to point out animals (including humans) respond more favorably to positive reinforcement than they do to punishment. In other words, if you want to train your dog, cat or spouse it is more effective to reward good behavior than to punish bad behavior.
A news item in the February 15, 2008 issue of the Journal of the American Veterinary Medical Association reinforces that notion. Here is an excerpt.
The American Veterinary Society of Animal Behavior has issued a position statement and guidelines on the use of punishment for dealing with behavior problems in animals.
The guidelines clarify that while punishment can be effective in specific contexts, it also has an association with many adverse effects.
The news item goes on to point out that punishment, as it is employed by most people, is ineffective. In fact, it can lead to increases in undesirable behaviors such as aggression. It can weaken the bond between the punisher and the punished, and it may cause animals to become generally fearful.
Many people punish their pets out of anger, do not use punishments consistently, or time punishments inappropriately. Unless you have training in animal behavior, it is unlikely that punishing your pet will bring about desirable behavior changes.
So there you have it. The next time you come home and find garbage strewn all over the house, resist the urge to yell at the dog. It might help you blow off steam, but it won’t keep your pet out of the trash in the future.