Horses can actually pout and smile, and widen their eyes in response to feelings. A new study published in the journal PLOS ONE has shown that horses have similar facial expressions to humans.
Horse faces have proved to be more similar to ours that we would have thought. A wide range of facial expressions of the animals were mapped out by the researchers. They did so by analysing horse video footage for 15 hours and by dissecting a horse head to examine its musculature.
“Horses and humans are distantly related and have such differently shaped faces that I personally thought there would be really no similarities,” says the author, Jennifer Wathan, a PhD candidate from the University of Sussex in the U.K. “But there was a surprising amount of similarities.”
They developed a map of the face of a horse using a technique known as Facial Action Coding Systems (FACS) to measure facial movement.
Humans make 27 separate facial movements, while chimps make 13, and dogs make 16. Horses turned out to have 17 in all.
“Most people who have horses know they are expressive and use their ears a lot, but I’ve got to admit, I was really surprised by the extent to which they use their face,” Wathan says. “They’ve got a huge facial repertoire.”
Now, why do humans and horses have such similarities?
“Whether animals communicate intentionally is still a huge and fairly contested issue,” she says. But three of our shared expressions particularly captivated Wathan. “One is raising the inner eyebrows,” she says—something humans do when we’re scared, surprised or sad. “You know, puppy-dog eyes,”she says.
“They think that’s potentially because it enhances the proportions of the dog’s face to make them look more like human babies,” Wathan says. “It taps into our sensory biases to provide care for human babies.” Horses also do this expression, she says, “and it seems that they do it in negative emotional situations, too.”
Horses and humans both pull the corners of their lips back for smiling, which might be representative of submissiveness in the former.
“It seems to be part of the submissive gesture,” she says, and younger horses tend to do it to older horses.
Horses were also found to widen their eyes when experiencing fear. Another trait similar to humans.
“The ability to use complex facial expressions was one of these things that was kind of touted as being uniquely human,” Wathan says. “But other species are doing it, and we share these abilities with all the other species around us.”