A recent study has shown that dogs can sense if you are happy or sad. For his study Corsin Müller selected 11 dogs. The dogs were nine Border Collies, a Fox Terrier, and a Sheltie. The experiment started with exposing dogs with digital images of woman that were either happy or angry. What the dogs had to do was tough the screen with their nose. Half of the dogs touched the face with the happy face and the other half angry face. Even if the dogs picked happy or sad expressions they were all rewarded with a treat.
What was interesting about this was that the dogs were not always given the full face. Scientists showed the dogs the faces like this because scientists believe that you show your expressions on your entire face and not just a certain part. By showing the dog part of the face is teaching them to recognize small details/things.
While the scientists were observing the dogs they noticed that the dogs that are being trained to recognize the angry expressions took longer to learn.
Later the dogs identified all the expressions, which proves that dogs can tell if your happy or sad.