Dogs have been domesticated for longer than any other animal on the planet, and humans have developed a unique relationship with these furry friends. We treat our pets like a part of the family, and feel that they can understand us in a way other animals can't. Now, new research is revealing what dog lovers have suspected all along: Dogs have an uncanny ability to read and respond to human emotions. Humans, in turn, respond to dogs with the same hormone responsible for bonding mothers to their babies. How did this incredible relationship between humans and dogs come to be? And how can dogs, so closely related to fearsome wild wolves, behave so differently?