The Evolution Of Puppy Dog Eyes

“Aww, look at that cute little puppy face!”

Almost everyone who has dogs of their own, or knows people with pet dogs, have experienced the almost hypnotic and adorable effects of those big round puppy dog eyes. It’s hard to say no to a dog when they simply look too cute for words. It’s a look that is difficult to stay mad at even when they have done something wrong.

Have you ever wondered why you’re such a sucker for those big, sad puppy eyes? Well, according to scientific research, this is more than just an adorable doggy feature. It was concluded in a recent study published in Proceedings of the National Academy of Sciences (PNAS) that there is a very distinct difference in the anatomy between wolves and dogs. Studies showed that the facial structure and physiognomy of both species were very similar when compared, except for the eyes. 

Dogs evolved and developed a muscle called the levator anguli oculi medialis, a muscle not found in wolves. This muscle allows dogs to raise the inner part of their eyebrow, allowing them to express their “sad eyes” or more popularly known as “puppy dog eyes.”

Research showed that dogs evolved this way due to their relationship with humans. This expression evokes a nurturing response in humans, as it almost mimics the adorable, yet sad or juvenile, facial expression in human babies. Puppy dog eyes allow dogs to not only better communicate with humans but also to create a stronger and more profound bond with them, and ultimately capture their hearts.