Research has shown that some species of monkeys, birds and domesticated animals can even distinguish among different faces by looking at photographs alone. Scientists have also wondered whether domesticated animals that have coexisted with people for thousands of years can recognize different human faces.
Léa Lansade of the French National Research Institute did an experiment to find out how well horses can recognize individual people in photographs. She and her team first taught the horse show to "choose" between two side-by-side images by touching their noses to a computer screen. The horses were then shown photos of their current keeper alongside faces of unfamiliar humans. They had never seen photos of any of the people before. The horses correctly identified their current keeper and ignored the strangers face about 75 percent of the time, significantly better than chance. What's more, the horses also preferentially picked photos of their previous keeper—a person they hadn't seen in six months. In fact, even though the horses didn't get it right every single time, they were at least as accurate in picking out their previous keeper as they were at identifying their current one.
The results suggest that not only can horses tell the differences between familiar and unfamiliar human faces, they can also understand that photographs are representations of real life. In addition, horses seem to have a long-term memory for human faces.
In future experiments, the researchers would like to test whether looking at photos of people that they have had bad experiences within the past might cause horses to act anxious or even avoidant. So maybe think twice before doing anything that might give a horse a long face.
