To be fair, there was nothing wrong with Cato. He was a discarded plotthound whose innate skillset was not well-matched to a suburban lifestyle. There are millions of dogs in the same predicament.
One of the findings from the MRI project is that the part of the canine brain associated with reward can respond to different types of reward. When we began, we focused on how this part of the brain responded to food. But this was just a proof of concept. Since then, we have been measuring how the dog's reward system responds to social signals like the presence or absence of their humans, or the smell of their human. We have even begun measuring the brain's response to pictures of their humans. It is becoming clear that dogs, like people, respond to these types of social signals regardless of the form they come in. And this tells us something important about living with difficult dogs.
Dogs have free will. They make choices. If they do not do what we want them to, then it is because a more attractive alternative has captured their interest. The usual way that humans attempt to bend dogs to their will is by changing the value of the options. With "positive training," the value of the desired action is increased by associating it with food or play. This is very effective for most things that a dog should learn, like walking calmly on a leash or coming when called. However, there are certain circumstances in which no amount of food or praise will divert a dog from his intent. If a dog really wants to chase a squirrel, there may be nothing you can offer that will be of higher value. It is in these circumstances that humans will resort to what many trainers have called the dark side: punishment. By definition, anything that decreases a behavior is a punishment. A leash correction is a punishment. Blocking your dog from running out the front door is a punishment. Yelling, hitting, shock collars are all punishments.