Only a few animal species are able to recognize their own reflection in a mirror. Horses are added to this short list. Details of this work are published in the journal Animal cognition.
The mirror test
In cognitive ethology, the mirror test makes it possible to evaluate the recognition of one’s body. Initially, animals tend to react socially, acting as if this reflection is another animal. After a while, this response tends to subside. Most then move on, but some react differently and continue to show interest in that reflection. Do they understand that it is about the projection of their own body?
To determine this, the scientists pass them the mirror test developed by the American Gordon G. Gallup. The principle is simple: the animal is marked in a place that it can only see in the mirror (usually on the forehead or ears). Then, the researchers observe if the subject spends more time attempting to touch that part of the body in front of the mirror when it is marked than when it is not. If so, it suggests that the animal recognizes its reflection.
This test was first used and successful in the 1970s with chimpanzees. Since then, other species have distinguished themselves. In addition to humans (over 18 months), we can mention orangutans, bonobos, chimpanzees, but also orcas, Bottlenose dolphins, false killer whales, Asian elephants and pigs. In birds, two species passed this test: Gabonese gray parrots and black-billed magpies. Finally, among fish, the common cleaning wrasse and the manta ray are distinguished.
As you can see, the list is quite short… but it just got longer.
Horses recognize their own body
Italian researchers have indeed found evidence of self-recognition in horses.
As part of this work, several horses were placed in front of a large mirror in a dressage arena, the time to get used to it. After the horses stopped responding socially to this mirror, the researchers drew a cross-shaped mark on both of their cheeks using a colorless ultrasound gel. In a second experiment, the horses were marked in the same way, but with a colored ultrasound gel.
The researchers then observed and analyzed the behavior of the subjects. The goal was then to know if the latter would be more interested in visible marks than in invisible marks. It did. The horses have indeed spent about five times longer trying to scratch your face in front of the mirror when they were visibly scarred.
According to the authors, these horses therefore became aware of the presence of these marks in the mirror and then understood that these marks were present on their own face. While we should be careful about generalizing these abilities from a single study, it does suggest that self-recognition (here thinking objectively about one’s own body) might therefore exist in horses as species.
Finally, a little reminder, like dogs or sheep, horses are also able to read our facial expressions, but also remember them. In other words, looking grumpy at a horse seems like the best way to alienate it.