Ah, puppy dog eyes. Nothing is so adorable, or so incredibly persuasive. Now, new research sheds light on why we are rendered powerless by that sweet doggie expression. Turns out, dogs developed new muscles around the eyes specifically to better communicate with humans.
In the first detailed analysis of its kind, a study published in Proceedings of the National Academy of Sciences compared the anatomy and behavior of dogs and wolves and found that dogs have a small muscle that allows them to intensely raise their inner eyebrows. Wolves, however, do not share this specific muscle.
"The evidence is compelling that dogs developed a muscle to raise the inner eyebrow after they were domesticated from wolves," said lead researcher Juliane Kaminski, PhD, in a press release. "We also studied dogs' and wolves' behavior, and when exposed to a human for two minutes, dogs raised their inner eyebrows more and at higher intensities than wolves."
Previous research has shown that pups move their eyebrows significantly more when humans are looking at them, compared to when they're looking away. Researchers think this is key to making dogs appear larger and infant-like, triggering a nurturing response in people. This interaction may also create the illusion of a human-like communication with our pups.
"The findings suggest that expressive eyebrows in dogs may be a result of humans unconscious preferences that influenced selection during domestication," said Kaminski. "When dogs make the movement, it seems to elicit a strong desire in humans to look after them. This would give dogs, that move their eyebrows more, a selection advantage over others and reinforce the 'puppy dog eyes' trait for future generations."
No wonder why we think of dogs as our fur babies!
Next, watch this video of good dogs reacting to being told how good they are: