Can pets read human emotions?

I know for a fact that my dog can read my emotions. It is amazing how he reacts to my own emotions. Sometimes, when I am sad, he will come to me and sit next to me. He then proceeds to lick my arm in a way that it feels like he's trying to treat the wound. His warmness being next to me and the way he tries to cure me usually makes me feel better. He can tell when I am happy as well, he usually responds a lot faster and has a sort of "smile" so to speak. Dogs are amazing.