Previous research we’ve highlighted on our blog suggested that humans are quite good at reading their pet dog’s facial expressions. But what about the other way around? How good are dogs at reading their owners’ emotions?

Up until now, scientific evidence and research in this realm was lacking, but a new study finds that dogs are able to tell the difference between happy and angry human facial expressions.

Biologist Corsin Muller of the University of Veterinary Medicine in Austria and his colleagues tested 11 dogs using a touchscreen. They trained the dogs to touch either a happy or angry face for a treat. They presented the dogs with their the top half or the bottom half of the faces to ensure the animals weren’t just responding to a smile or baring of the teeth.

The pets trained to pick out happy expressions could do so when presented with different halves of a face, as well as when presented with faces the animals hadn’t seen before.

The dogs trained to respond to angry faces were also able to pick out angry expressions among the choices they were asked to make. However, it took them longer to learn their task than the dogs trained on happy faces.

Researchers don’t yet know whether the dogs’ ability to discriminate between the two expressions is because of past experiences or the result of the domestication process. While primates are known to recognize faces, dogs may have been especially adapted for emotional sensitivity to humans during their domestication. The researchers plan to investigate how common this ability is by testing pigs and other animals.