A scientific look at the question
Aaaah that look your dog gives you when you eat something in front of him that makes him crave! All dog owners know him well. You know, that "beaten dog look" with which your dog stares at you, with big eyes, both a little sad and full of hope and tenderness. Well, a team of scientists took a very close look at it and published their findings on June 17, 2019 in the Proceedings of the American Academy of Sciences (Pnas).
Brow muscles that only exist in dogs
To conduct their study, the researchers focused on one muscle group in particular, the eyebrow muscles. About him, they discovered that these muscles only existed in the domestic dog but not in its closest cousin, the gray wolf. Before coming to this discovery, the researchers studied domestic dogs and wild wolves, two species of canids that diverged around 33,000 years ago. In dogs, two well-formed muscles around the eyes were highlighted, while in wolves only one tendon was found instead of this muscle.
The other part of the study consisted in filming short encounters between an animal and a human who was unknown to them. Result: only dogs managed to move their eyebrows when they looked at humans.
The tender gaze of the dog would therefore be the result of the contraction of these eyebrow muscles. Its function would be to help them “enlarge their eyes”. But do they do it for the sole purpose of softening us?
An expressive look, a selective advantage
It triggers a protective response in people, Anne Burrows, a professor at Duquesne University in Pittsburgh and co-author of the study told AFP.
And, indeed, this movement of the eyebrows has the effect of enlarging their eyes and giving them a facial expression close to that of a puppy or child, which naturally has the effect of softening their eyes. Human being. This study thus echoes a completely different scientific study, conducted by Japanese researchers in 2015. It had shown that the exchange of looks between dogs and their masters caused a mutual peak in oxytocin, the hormone of attachment. and maternal love.
This study also highlights how the dog has developed, during its evolution, new means of communication, specific to the interactions it has had with humans for millennia.
To go further, another study from 2013 even suggests that dogs could even have been selected, naturally or unconsciously by humans, thanks to this type of characteristic. At the time when dogs lived free in villages, it is a safe bet that the most expressive dogs received more food than the others. Likewise, our subconscious preference for dogs that had this expression most likely influenced our selection. Proof of this is today with shelter dogs. We know that dogs with more expressive eyes than others are more likely to be adopted than their companions in misfortune with less endearing eyes.