Formal dog training as we know it originated during World War II. Before that, dogs had been working household members and their behavior was largely shaped through organic learning from older dogs. Only when soldiers needed to train large numbers of dogs to assist in warfare did compulsion training arise and, when the war ended, was developed into a recognized field by discharged military personnel. Back then, society as a whole accepted punishment as a valid teaching method. Typical training approaches involved physical corrections, leash jerks, and loudly yelling at the dog. This was difficult for puppies to endure, so the prevailing wisdom was to hold off on proper training until the puppy was seven months old (house-training was the exception). In some places, these outdated methods are still used. But from the 60s and 70s and on—through the work of pioneers like Bob Bailey, Karen Pryor, and Dr.