Horses and Humans Share Lots of Looks
Researchers have observed 17 distinct facial expressions in horses
By Elizabeth Armstrong Moore,  Newser Staff
Posted Aug 6, 2015 11:33 AM CDT
Assistant trainer Jimmy Barnes holds Triple Crown winner American Pharoah as they stand in the stable area at Monmouth Park in Oceanport, N.J., Saturday, Aug. 1, 2015.   (AP Photo/Mel Evans)

(Newser) – Scientists at the University of Sussex have taken a long, hard long at our equine pals and determined that horses have 17 distinct looks of their own. Some 15 hours of observing natural behavior in 86 horses, ranging in age from four weeks to 27 years and spanning several breeds, have yielded that number of facial expressions, they report in the journal PLoS One. That's three more than chimps use, one more than dogs, and only 10 fewer than humans, reports the Guardian. They call their system Equine Facial Action Coding System (EquiFACS), and while they've managed to identify the facial movements horses can make, "The challenge now is to document what contexts these occur in, and then we will be able to make more informed comparisons," says Jennifer Watham, one of the lead authors.

What surprised her the most, she tells Discovery, is that "we didn't expect horses to have any similarities with humans at all—they're two such distantly related species and, at first glance, have such differently shaped faces." But with better vision than cats and dogs, horses are visual animals, and appear to have developed incredibly nuanced expressions. For instance, both horses and humans are capable of raising the skin above their eyes, as well as retracting the corners of their mouths. Whether these expressions mean similar things across species remains to be seen, but the researchers surmise that in the evolution of equine facial expressions, social factors are at play. (Who's faster, horses or people?)