A new study conducted by psychologists at Sussex University has revealed the surprising sophistication of horses’ social capabilities. They’re able to recognize human emotions through facial expressions and can even do so through a picture. The team showed large prints of human faces—both smiling and frowning—to 28 horses, and their reactions were clear. Horses reacting to angry facial expressions had an increase in heart rate and turned their head to look at the face with their left eye—the eye most closely linked to the part of the brain that deals with scary stimuli. Read more about the discovery at The Guardian.