PARIS: Dogs have been man’s best friend for 30,000 years and scientists have now discovered the secret to that long companionship – they can read our emotions.
The researchers discovered dogs were able to tell simply from looking at a human facial expression whether that person was happy or angry.
The discovery represents the first solid evidence that an animal other than humans can discriminate between emotional expressions in another species.
Professor Ludwig Huber of the University of Veterinary Medicine Vienna said: “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.”
For the study, published in the Cell Press journal Current Biology, the researchers trained dogs to discriminate between images of the same person making either a happy or an angry face.
In every case, the dogs were shown only the upper or the lower half of the face.
After training on 15 picture pairs, the dogs were tested in four types of trials that involved looking at new faces or different parts of the faces they had already seen.
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.
Dr Corsin Müller added: “We think the dogs in our study could have solved the task only by applying their knowledge of emotional expressions in humans to the unfamiliar pictures we presented to them.”
Professor Huber said it was hard to say what seeing a happy or an angry face meant for individual dogs, “but it appears likely to us that the dogs associate a smiling face with a positive meaning and an angry facial expression with a negative meaning” he added.
