A horse walks into a bar.
“Why the long face?” asks the bartender.
Scientists at the University of Sussex must have heard that old joke and taken it seriously. They have discovered that horses are able to employ seventeen distinct facial expressions—three more than chimpanzees and one more than dogs. Humans, by way of comparison, are able to communicate their most subtle feelings by twenty-seven different facial expressions through our exceedingly dexterous facial musculature.