Dogs. Everyone knows they're "man's best friend," right? Cute, cuddly, loyal, and full of unconditional love, dogs evolved alongside us as our stalwart and faithful companions. They're good people. Or maybe that's just what they want you to think.
If you've ever even seen a dog, you're well aware of the "puppy dog eyes" they throw at you: that sad, inquisitive face with their eyebrows raised that makes you truly believe that they need your porterhouse steak more than you do. Well, new research has shown that the sad puppy face is an evolutionary adaptation meant to emotionally manipulate us. And as anyone who has ever even seen a dog would also know, they're pretty good at it.
The new research, published in the journal PNAS, compared the muscular structure of wolves and domesticated dogs and found that dogs have extra muscles that allow them to communicate with humans. Specifically, researchers found muscles around the eyes of dogs that allow them to "intensely" raise their eyebrows, something that wolves cannot do. The study found that these eyebrow muscles allow dogs to make their eyes "appear larger, more infant like and also resembles a movement humans produce when they are sad." The end result of this adorable manipulation is to provoke a "nurturing response" in humans. In a statement, comparative psychologist at the University of Portsmouth and lead author of the study, Juliane Kaminski, said:
"The findings suggest that expressive eyebrows in dogs may be a result of humans' unconscious preferences that influenced selection during domestication. When dogs make the movement, it seems to elicit a strong desire in humans to look after them."
The study also compared the faces made by dogs and wolves in the company of humans. Placing both canine species in close proximity to a human for two minute intervals showed that domesticated dogs would raise their eyebrows more intensely and with greater frequency than wolves.
Researchers believe that because humans are more likely to nurture a sad puppy dog face, the trait had a selection advantage and was thus reinforced through the generations after domesticated dogs split off from wolves, a split which occurred roughly 33,000 years ago. Anne Burrows, co-author of the paper, says:
"The raised inner eyebrow movement in dogs is driven by a muscle which doesn't consistently exist in their closest living relative, the wolf. This is a striking difference for species separated only 33,000 years ago and we think that the remarkably fast facial muscular changes can be directly linked to dogs' enhanced social interaction with humans."
So when your dog looks sad, just remember it's simply a trick of evolution meant to elicit a nurturing response from you. Which is literally the same exact thing as when a person looks sad. If there was no reason to show emotion, we'd all be walking around like stone-faced psychopaths. Or cats. This all sounds like cat propaganda to me. Dogs are good people and that's my hill to die on.