Why Do Dogs Have Such Expressive Eyebrows?

Fenrir’s (my Alaskan Klee Kai) eyebrows really crack me up!  Most of the fur around his face is gray, but his eyebrows are all white.  It gives him quite a distinct look.  I joke that if my dogs could talk, the one thing of Fen’s that my Papillon, Kitsune, would be jealous of would be his dignified brows.  Truth be told, despite not standing out quite as much, Kitsune’s brow game is pretty on point too.  Have you ever wondered why dogs have such expressive eyebrows when compared to most other members of the animal kingdom?

Did you know that dogs, like humans, use their eyebrows to express emotion?

I suppose all dog owners will already know that, though.  Sad puppy dog eyes anyone?  Besides humans and other primates, there’s not a ton of animal species that use their eyebrows to outwardly express emotions.  Wolves, although social and highly communicative with each other, don’t express emotions with their eyes in the same way that our domestic dogs do.  In fact, domestic dogs have muscles in their eyebrows that don’t even exist in wolves!

That’s Evolution For Ya!

These muscles allow dogs to control their eyebrows in ways that wolves, and other animals, cannot.  Specifically, dogs are able to raise their inner eyebrows.  This movement opens their eyes wider, and makes their eyes appear larger – aka…puppy dog eyes!

Take a look at this study, Evolution of facial muscle anatomy in dogs, published in 2019.  If you scroll down a bit, to the results section, you can see a diagram that illustrates the difference in facial musculature between domestic dogs and wolves.

Basically, humans are suckers for puppy dog eyes.  Over time, we selected for dogs with more pronounced eyebrow movements.  Perhaps we can relate better to dogs who use their eyebrows in a similar way to how we use our own?  Or maybe we just find dogs who are more expressive to be cuter?

Having More Expressive Eyebrows Benefits Dogs.

Studies have suggested that shelter dogs with more expressive eyebrows are more likely to get adopted faster!

The study Paedomorphic Facial Expressions Give Dogs a Selective Advantage was published back in 2013, but the results are still really interesting today.  Researchers tested how facial expressions that enhance dog’s neonatal (childlike) appearance impacts how quickly they are adopted from shelters.  According to the study, dogs who raised their inner brows more often found new homes faster than their less expressive counterparts.  This is, theoretically, because manipulating their eyebrows in this manner effects their eye size and height, making them look more childlike, and thus cuter.

It seems like those puppy dog eyes, so famous for helping dogs to beg for bits of extra dinner, involve more than just the eyes themselves.  There’s some serious brow work going on too!

What do you think?  Comment below!  Does your dog use certain facial expressions to try to manipulate you?  Kit and Fen seem to have thoroughly perfected the sad puppy look.  It’s totally hard to resist giving them what they want when they give me ‘the look’.  I guess I have thousands of years of evolution to thank for that!