There are approximately 43 million households in America that have one or more dogs as part of the family bringing the total up to some 73 million dogs. Some fall into the Service Dog category in which they provide assistance to the blind, disabled veterans and help with mental disabilities such as autism. Programs have even been adopted in prisons where inmates are given the responsibility of training a puppy. But what makes dogs so responsive to our needs? Does it have to do strictly with being devoted to the hand that feeds them or does it go deeper. Dr. Gregory Berns a neuroscientist at the Emory University in Atlanta has been scanning the brains of dogs to find out how exactly they think and what is their motivation. The process of using an M.R.I. was difficult because of the hearing sensitivity. When the process of getting a dog into an M.R.I. scanner was finally mastered some 90 dogs were scanned to see if their brains functioned along the lines of a human. The tests proved that dogs use the corresponding parts of their brain to solve tasks. About 25% of the dogs responded more to praise rather then to food. It was also discovered the dogs have the capability of responding to a photo of someone that they have an extreme devotion to. Could understanding a dog’s brain lead to solving why certain animals tend to be aggressive? If so, would it eventually help us in discovering the key to understanding aggressive behavior in humans?