If you are like me, you think “what a beautiful animal” when you see a photo of a wolf. But when you look at a photo of a dog you are more likely to think “what a cute dog!” especially if the focus is on the dog’s face.

Researchers recently published a paper in the Proceedings of the National Academy of Sciences journal that may help explain this diverging of emotional responses to the dog vs the wolf.

The study found that there is a difference in the size and frequency/intensity of use of a facial muscle when comparing dogs to wolves. The particular muscle is responsible for moving the inner “eyebrow” region.

So what?

Well, movement of that muscle is what gives dogs that sweet puppy dog expression. You know - the look that makes you want to take home all the dogs at the animal shelter.

Why is there this difference between dogs and wolves?

The researchers hypothesize (and I, in my humble opinion, agree) that dogs have a larger muscle and tend to use it more because we made them that way through our selection biases. It isn’t clear if we intentionally selected for this trait during the domestication process, but conscious or unconscious our preferences had a profound effect on the anatomy and behavior of the dog.

I think that’s why we like dogs so much. They are a reflection of ourselves - in the best sort of way.

Click here to read the study and see some cool videos of dogs and wolves.