Researchers say dogs know the difference between happy and sad faces

Findings of a new study have revealed another interesting fact about animals long said to be man’s best friends. Though dog owners and lovers can appreciate the fact that these animals can make out the difference between the ‘tone’, it has now been proved beyond doubt that they can also make out the difference between happy and sad faces.

Simply looking at a human face and looking at their facial expressions can let these wonderful creatures judge whether the person is happy or angry.

Researchers came to this conclusion after a series of experiments conducted by them at the University of Veterinary medicine Vienna. During the course of these experiments, the dogs were shown a person’s face in various emotional states but they were either shown only the upper half or the lower half of the face. Then they were shown different images than the ones used for training purposes, and given either a different half of a face seen by them already or a different person’s top or lower half of the face.

The researchers saw that dogs rewarded for picking happy faces more quickly learned how to tell happy and angry faces apart than those rewarded for picking angry faces. That, according to the study “would be predicted if the dogs recognized an angry face as an aversive stimulus.”

The dogs were able to select the angry or happy face more often than would be expected by random chance in every case, the study found. The findings show that not only could the dogs learn to identify facial expressions, but they were also able to transfer what they learned in training to new cues.

“Our study demonstrates that dogs can distinguish angry and happy expressions in humans, they can tell that these two expressions have different meanings, and they can do this not only for people they know well, but even for faces they have never seen before,” said Professor Ludwig Huber, University of Veterinary Medicine Vienna.

Researchers also observed that the canines were slower in associating with an angry face, which they say was based on earlier idea based upon experience that they prefer to look away from people who look angry.