Dogs Know a Smile When They See One

Dogs can differentiate between happy and angry faces from photos on a touchscreen, according to scientists at the University of Veterinary Medicine Vienna. Dogs trained to choose happy faces mastered the task significantly faster than those trained to choose angry faces.

To exclude the possibility that the animals were making their decisions based on conspicuous differences between two pictures, such as teeth or frown lines, researchers split the images horizontally so that during the training phase dogs saw only the mouth region or only the eye region, according to an online ScienceDaily report based on research published in the journal Current Biology.

Most of the dogs learned to differentiate between the happy and angry face halves. They also managed to identify the mood in novel faces as well as in face halves that they had not seen during the training phase.

“It seems that dogs dislike approaching angry faces,” ScienceDaily quoted study director Ludwig Huber. “It had been unknown that dogs could recognize human emotions in this way.”

“We believe that dogs draw on their memory during this exercise,” said first author Corsin Muller. “They recognize a facial expression which they have already stored. We suspect that dogs that have no experience with people would perform worse or could not solve the task at all.”

Good oral health improves a person’s ability to speak, smile, smell, taste, touch, chew, swallow and make facial expressions to show feelings and emotions. For “8 Great Ways to Improve Your Smile” visit the American Dental Association’s consumer website,

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