Canines Evolved a Special Muscle to Make Those Disarming ‘Puppy Dog

Angela Vuckovic
by Angela Vuckovic
If you find it too hard to resist to your pet’s pleading puppy dog eyes or completely melt at your pet’s slanted eyebrows when they try to figure out something, it seems that it’s all about evolution. A new study reveals another piece of the puzzle that is the human-canine communication.

We all know THAT look. The slanted eyebrows that make your dog’s eyes appear larger, sadder, and more appealing to humans. In other words, the look perfectly tailored to manipulate a treat, a walk to the park, or a belly rub out of you. But, if you thought that these devious and adorable tactics are unique to your pooch, you’ve been sorely mistaken. A team of scientists revealed that the so-called puppy dog eyes are a product of evolution and that all dogs are using this facial expression to communicate.

The study published in Proceedings of the National Academy of Sciences speaks about the effects of domestication on the very anatomy of dogs- as well as the purpose of these evolutionary changes. What we usually call the puppy dog eyes, scientists have dubbed ‘AU101: inner eyebrow raise’. Their findings indicate that the muscle responsible for the inner eyebrow raise is present in dogs but not in wolves- which also coincides with the fact that dogs do make more facial expressions that involve eyebrows than their wild cousins do.

The scientists hypothesize that the reason why dogs have evolved to make that particular face is to trigger a nurturing response in humans. (And, boy, does it work.) The idea is that the puppy dog eyes were the result of selection based on human preferences: the expression is similar to that we make when sad, so it’s perfect for tugging on heartstrings, in a nutshell.

Additionally, as the study involved dogs of various breeds and a mutt, scientists were able to determine that Siberian Huskies, like the wolves, don’t have the inner eyebrow muscle needed to make the soulful face that knocks us off our feet. That might be the reason why they are so vocal in their attempts of communication? Who knows!

In the end, it seems that there is a lot we are yet to find out about our intricate relationship with dogs. But until then, the next time your pooch manages to trick you for an extra treat with his big, soulful eyes, don’t feel bad. After all, it’s a ploy that’s been 33,000 years in the making. How could anybody resist?

Angela Vuckovic
Angela Vuckovic

A proud mama to seven dogs and ten cats, Angela spends her days writing for her fellow pet parents and pampering her furballs, all of whom are rescues. When she's not gushing over her adorable cats or playing with her dogs, she can be found curled up with a good fantasy book.

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