Dogs Able to Read People's Feelings, According to New Study

Dogs are considered as man's best friend for a very good reason.

A study by researchers in Vienna, Austria, found that dogs can be trained to read facial expressions. "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," biologist Corsin Müller of the University of Veterinary Medicine Vienna was quoted by New York Daily News as saying.

Using a touch screen, 11 dogs – including border collies, a fox terrier, a golden retriever, a German shepherd, and some mutts – were tested. The scientists trained the dogs to touch either a happy face or an angry face for a treat, National Geographic wrote on Thursday.

Researchers showed dogs with either the top half or the bottom half of human faces to make sure animals are not just responding to a smile or baring of teeth.

Müller said emotions show on all parts of a human face, not just the mouth. "If you're angry, a wrinkle between the eyes shows up," he said. The shape of the eyes can also change.

After the training period, researchers tested the canines' ability to distinguish between the two emotions through choice trials, in which the dogs had to pick between strange faces with either happy or angry expressions.

The pooches were shown with either the top, bottom, or left half of a face, as previous studies found that dogs prefer to look at the left side of a face.

"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," wrote National Geographic. "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."

The longer time may be due to the dogs connecting negative associations with angry faces. Angry faces may mean a dog will not receive pats while happy faces will mean a belly rub, Müller suggested.

"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, senior author and head of the group at the University of Veterinary Medicine Vienna's Messerli Research Institute.

It is yet to be known if the dogs' ability to differentiate between the two emotions is due to their past experiences or the domestication process.

Whatever the reason may be, Müller said dogs can tell the difference "because they spend so much time with humans, they have a lot of opportunities to see human expressions."

The study's finding was published in the journal Current Biology.