We can spot an angry dog – but not a sad one

PEOPLE struggle to know when their dog is sad, scientists have found – but they are able to tell if their pet is angry.

Lasana Harris, professor of social neuroscience at University College London, led two studies that involved 179 people to see if humans were better at understanding the facial expressions of dogs or chimps and bonobos.

He found people were much better at identifying how dogs were feeling than the apes, probably as a result of millennia spent living and working together.

Five emotions were scrutinised: happiness, fear, anger, sadness and a neutral state. The researchers found people were best at recognising anger, followed by happiness and “neutral” – which they saw as the same – with sadness and fear equally poorly detected.

“One of the interesting findings is that people were better at spotting anger across species,” said Prof Harris.

“An angry face looking directly at you is threatening, so people seem to have the ability to pick out this emotion best, regardless of the species they are looking at, as it ensures our survival.”

Survival is not dependent on detecting sadness and fear, however, which is likely why humans struggle to identify them in both dogs and apes.

“A popular theory surrounding domestication of dogs is that a lack of aggression allowed wolf pups to enter campsites and remain with huntergatherer humans,” said Harris. “Therefore, we pay attention to safety signals from dogs, and joy/pleasure expressions are certainly that.

“I think sadness and fear don’t hold the same evolutionary importance, and as a result, people attended to them less.”

The study found that people can tell how dogs are feeling better than they can with their fellow primates.

People were better able to understand dogs the more time they spent with them, whereas this was not seen with apes.

The findings are published in the journal