Horses and Humans Share Facial Expressions

Two facial communication arrays. gilaxia/Getty Images

I've never been an equestrian, but I appreciate my wife and her aunt's affinity for horses. I loved Cormac McCarthy's beautiful descriptions of the horse's soul in "The Border Trilogy." So this latest University of Sussex study about horse facial communication really called to me.

It's easy to mistake the horse as a non-expressive creature, but riders will correct you rather quickly on the matter. We can read their temperament and communicate our intent, if only we come to know them. But facial communication? Sure, human faces serve as key communication arrays, but surely the face of the horse is less expressive.

Equine anatomy, 1618, by Carlo Ruini,
Universal History Archive/UIG/Getty

Not so, according to the 2015 study published today in PLOS ONE. As it turns out, Horses share some surprisingly similar facial expressions with humans and chimpanzees.

Just like us, horses use muscles underlying various facial features (nostrils, lips and eyes) to express emotional states. The researchers' Equine Facial Action Coding System ("EquiFACS," for real) identified a whopping 17 discrete facial movements in horses. That's compared to 27 in humans, 16 in dogs and 13 in chimps.

That's right: Horses display more facial emotion than man's best friend or man's closest evolutionary relative.

After all, as prey animals, horses are highly visible creatures. Co-lead author Jennifer Wathan even went so far as to describe horses as possessing a " rich repertoire of complex facial movements," many similar to humans despite our vastly different cranial structures.

So think about that the next time you stare into the eye -- into the soul of the horse.

"He spoke of his campaigns in the deserts of Mexico and he told them of horses killed under him and he said that the souls of horses mirror the souls of men more closely than men suppose and that horses also love war." - Cormac McCarthy, "All the Pretty Horses"

About the Author: Robert Lamb spent his childhood reading books and staring into the woods — first in Newfoundland, Canada and then in rural Tennessee. There was also a long stretch in which he was terrified of alien abduction. He earned a degree in creative writing. He taught high school and then attended journalism school. He wrote for the smallest of small-town newspapers before finally becoming a full-time science writer and podcaster. He’s currently a senior writer at HowStuffWorks and has co-hosted the science podcast Stuff to Blow Your Mind since its inception in 2010. In his spare time, he enjoys traveling with his wife Bonnie, discussing dinosaurs with his son Bastian and crafting the occasional work of fiction.