09/05/2026
🐴 Twenty-eight horses were shown nothing but a photograph of a stranger's face, and their heart rates rose faster, and they turned their left eye toward it, when the face in the picture was angry.
The study was published in Biology Letters in February 2016 by Amy Smith, Leanne Proops, Kate Grounds, Jennifer Wathan and Karen McComb of the University of Sussex. Horses at riding yards across Sussex were shown large photographs of unfamiliar men, either angry or happy.
Two things were measurable. The horses preferred to view the angry faces with the left eye, and the left visual field feeds the right hemisphere, which in many species handles threat. Their heart rates also climbed more quickly.
The follow-up, in Current Biology on 26 April 2018, went further. McComb, Proops, Grounds and Smith showed horses a photograph of a person looking angry or happy, then introduced them to that actual person hours later, now with a neutral face. The horses behaved more negatively toward the individual they had seen photographed angry. The effect was person-specific, and did not spread to anyone else.
The horses had never met these people. Everything they responded to came off photographic paper, which rules out scent, voice, tension on the rein and any unconscious cue from a handler.
Do you think your horse reads your face, or your body?
