Dogs can differentiate between humans’ angry and happy faces

Research provides the first evidence that animals can recognise our expressions

Dogs can tell different human facial expressions

Everyone knows that dogs are a man’s best friend – and now scientists have shown they can read our faces.

Researchers in Vienna have established that dogs are able to tell the difference between angry and happy human expressions. They say this is the first credible evidence of any non-human animal being able to recognise the countenance of another species.

“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 Ludwig Huber, of the University of Veterinary Medicine Vienna. “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 said.

The findings are based on a series of tests in which two groups of dogs were shown a sequence of human photographs.One group was rewarded with food for touching pictures of people looking happy with their paws and the other for identifying those looking angry.

The food was dispensed automatically below the touchscreen every time the computer registered a correct response. The dogs were able to select the angry or happy face more often than would be expected by random chance in every case, found the study, which also involved the Medical University of Vienna and the University of Vienna.

It is published in the journal Current Biology. “Further work will be needed to figure out the behavioural and physiological consequences of observing emotions in others, for example whether dogs show what we call ‘emotional contagion’,” said co-author Corsin Muller, of the University of Veterinary Medicine Vienna.

Emotional contagion describes the process of being emotionally affected by another’s mood, such as becoming sad when observing somebody else being sad. The study builds on a long line of anecdotal and scientific research on the relationship between man and dog.

Previous studies have shown that dogs can discriminate between two-dimensional representations of familiar and unfamiliar human faces and suggested that they may show empathy when encountering a crying human.

Domestic dogs have also been found to be far more adept than other animals at reading human social and communicative behaviour, with research indicating they are much better at responding to a pointing gesture to find hidden food and understanding what humans can and cannot see in various situations.

The scientists believe that dogs evolved unusually good social skills during the process of domestication in which those that could communicate well with humans prospered.