By Dr. Becker
During the late 1800s, a mathematics teacher named Wilhelm Von Osten traveled across Germany with his intelligent horse, Clever Hans. Hans was able to count by tapping his hooves and even answer mathematical problems, spell out names, tell the time and decipher dates.
Hans became a sensation in his day, but years later it was determined that Hans was actually responding to subtle unconscious cues being given by his trainer. In order to answer the math problems and other questions correctly, he had to be in full view of the trainer, and the trainer needed to know the answer to the question.1
It turned out that Von Osten would unintentionally shift his posture, facial expressions and breathing, indicating tension, until Hans answered correctly. When the tension disappeared, Hans knew to stop tapping.
While Clever Hans wasn't able to do math as was once thought, he did show that horses are incredibly responsive to subtle shifts in human behavior — a marvel in itself. It also highlighted what would be a continued challenge in equine research: how to remove the risk of human influence on horses' decision making and actions.
Masaki Tomonaga, Ph.D., associate professor in the Kyoto University Primate Research Institute's Language and Intelligence Section, in Aichi, Japan, explained in The Horse:2
"This sensitivity to behavioral/social cues in horses itself should be examined more from the perspective of contemporary comparative cognitive science, but we should carefully avoid such inappropriate responses … One of the best ways is to use computer-controlled systems."
How Do Horses Discriminate Between Different Shapes and Sizes?
Tomonaga and colleagues have used touch-screen computers in tests involving chimpanzees, so they developed a similar system to use among horses.
The 42-inch touch-screen monitors showed horses different sizes or shapes. If the horse chose correctly by touching the appropriate choice with his nose, he was rewarded with a carrot, which was automatically distributed beneath the screen.3
The horses learned to use the screen quickly, and were presented with different letter combinations (in which X was always the wrong choice) and shapes of varying sizes.
The horses had more difficulty than chimpanzees and humans when it came to distinguishing between circles of similar sizes, which could be due to poorer eyesight. They did, however, use diameter more often than area to detect size differences, which is similar to humans and chimpanzees.
The horses were also able to identify shape differences similar to chimpanzees and humans, although the horses had more difficulty with closed shapes like squares, triangles and the letters O and D. The Horse noted:4
"In future studies, Tomonaga said computer screens will allow researchers to get more 'into the mind' of the horse, helping us see what he sees as he watches videos, for example.
Above all, the greatest benefit of the computer screen is the control of the experiment that takes the human out of the equation."
Horses Ask Humans for Help
Horses, like dogs, have been in close proximity, physically and emotionally speaking, with humans for thousands of years. Over that time, they've become quite adept at responding to human cues, as Clever Hans revealed, and recent research suggests they also communicate with humans when they need help.
Researchers from Kobe University in Japan hid carrots under a bucket and then made the bucket inaccessible to a group of eight horses.5 The horses' caretakers then entered the scene, unaware that food had been hidden nearby. Rather than just standing there, the horses began to ask their caretakers for help.
The horses looked at their caretakers, stayed close by them and nudged them, signaling that they needed a hand to get to the carrots. The behaviors continued for a significantly longer period of time than they did when no food had been hidden.
In a second experiment, the researchers examined whether the horses altered their behaviors based on the caretakers' knowledge of the hidden food.
It turned out that the horses' signaling behaviors significantly increased when the caretakers had not seen the hiding of the food, which suggests that horses likely have high social cognitive ability that likely developed during their domestication that occurred some 6,000 years ago.6
'Communication Could Be a 2-Way Street'
Studies like the computer touch-screen model and the one conducted by Kobe University are unique in that they give horses a voice, or at least a voice that humans can interpret. It's likely that horses are intelligent and capable of communicating with humans, if only we'd learn to listen.
Research published in 2016, for instance, showed horses can learn to use symbols to communicate their preferences.7 Within two weeks of training, and on average after just 11 days, every horse in the study (23 in all) learned to tell the researchers if they wanted a blanket put on or taken off, or if they wanted to remain unchanged.
It wasn't a random occurrence, as the horses chose to stay without a blanket in nice weather, and they chose to have a blanket on when the weather was wet, windy and cold.
Not only did they understand what each choice meant in terms of helping them stay warm or cool off, but they also learned how to communicate their preference to humans. As Wendy Williams, author of "The Horse: The Epic History of Our Noble Companion," told NPR:8
"For most of the history of horse domestication, we've assumed that communications between humans and horses was unidirectional. Humans order.
Horses obey. But in this study [Kobe University], we see that communication could be a two-way street. Horses do try to communicate with humans. Most of us just don't try to learn their language."