Why pet starts to behave “humanly”? This phenomenon does not require the creation of analogues of the Darwinian theory of the evolution of animal into man.
The answer lies in the fact that the dog “domesticated” from the tip of the nose to the tail under the systematic education and training of the person. So the dog begins to fulfill human requirements, forgetting or suppressing their animal instincts to bark and run around the apartment, jump on the owner, to hunt.
And therefore their energy, emotion dog expresses itself through the reproduction of facial expressions and movements. However, not all dogs can be seen distinct, clear smile and joy on his face. Therefore, the most smiling and joyful breeds are Spitz, Samoyed, Yorkie, Golden Retriever, Dalmatians and Corgi. Although any dog can be taught to imitate facial movements.