In a recent study done by the Canine Mind research project at the University of Helsinki, scientists discovered that dogs love their owner’s smiles so much that it can make things less threatening. This behavior is due to oxytocin, or the “love hormone,” which the brain releases in relation to love, trust, and attachment. Previous studies have shown that dogs release this love hormone when they look at their owner’s smiling faces.
The Canine Mind research group studied 43 dogs over the course of two tests. In the first, researchers administered oxytocin to each dog (after it was approved by an ethics committee and with full consent of the dog’s owners) and then showed each dog images of angry faces and smiling faces. They repeated this for the second test without the added oxytocin. Researchers tracked the dog’s emotional interest and attachment through pupil size and eye movements. Dogs without the influence of oxytocin were more interested in the angry faces. This reaction was likely due to the natural defense mechanism to danger.
However, researchers discovered that dogs under the influence of oxytocin were more interested in the smiling faces over the angry faces. It appears that, like humans, they prefer happier looking faces over threatening looking ones so much so that it will override the natural survival instinct in reaction to perceived threats. Researchers concluded that this discovery could help develop and promote human-dog interaction. Their results suggest that to best communicate with their dog, humans may want to smile to capture their full attention.