Scientists have isolated 27 discrete facial movements humans use to communicate, the most of any animal. Recent research conducted by the University of Sussex has found that horses use an impressive 17 distinct movements – one more than dogs and four more than primates. The study authors hope that their findings can help humans better understand the emotional lives of the animals we share our lives with.
The Sussex team began by dissecting a horse’s head to examine the unique musculature beneath the skin. Next, they examined 15 hours of behavioral footage featuring 86 male and female horses from a variety of breeds, ranging in age from four weeks to 27 years.
The final – and most innovative – step was to use a tool called EquiFACS (Equine Facial Action Coding System) which records and catalogues the eye, lip, nostril, and chin movements of the animal, resulting in a gestural map that suggests evolutionary parallels among varied species.
According to the study’s lead author, Jennifer Wathan, horse facial expressions and movements are strikingly similar to those of humans. For example, they raise their inner eyebrows (“puppy-dog eyes”) to show fear, surprise, or sadness; they pull back the corners of their lips (smile) in greeting or submission; and they open their eyes wide to indicate alarm.
In addition to helping us understand the inner thoughts and feelings of horses, EquiFACS could also shed light on the intricacies of interspecies relationships.
Wathan says the system could “create a common language to objectively make comparisons across species—even those with totally different-shaped faces.” EquiFACS is already being utilized by veterinarians and trainers.
H/t to National Geographic