Lukas is still a very excitable horse, as I saw when he first entered the paddock. Although he was clearly in pain from the bowed tendons, the bucks and the gallops and the midair twists were still there. But I could also see that Lukas is a naturally curious horse, like the horses Jason Ransom and I watched in Wyoming. When alone in the paddock, he began checking things out, even though he’d been there a thousand times before. He walked over to where a squirrel had scurried along a fence rail. Then he stood at attention scanning the horizon, wanting to know if anything out there had changed. He sniffed the water trough, put his nose into fence corners, and generally filled himself in on what had changed since his last visit, which had been only the day before. While I watched, he never really settled down and relaxed. He was always antsy, looking for whatever problems might be just around the bend.
But when Karen came into the paddock, he settled immediately. He walked over to her and invited her into their private world.
The dancing began.
* * *
According to scientists who study the evolution of emotions and of behavior, the biological basis for this kind of deep understanding between two seemingly very different species—this nurture that’s rooted in nature—comes from our shared natural history. “The difference in mind between man and the higher animals, great as it is, certainly is one of degree and not of kind,” Darwin wrote in The Descent of Man. For Victorians, this was downright risqué. To equate the mind of humans in any way with the mind of other animals was pushing the envelope.
Now we know that Darwin was half right and half wrong. In categorizing animals as “higher” and “lower,” he was buying into the Victorian belief that humanity was the pinnacle of evolution. Today we think about this differently. For example, we know that Equus is not “higher” than the long-gone Megahippus, but just better suited to the ecosystem in which he evolved. Today, rather than thinking about a ladder of life, we think about a web of life or even a jigsaw puzzle of life—to get the whole picture, we need to have all the pieces. We humans are indeed “special”—some of us can create great art or complex symphonies or even invent calculus—but we are also part of a system of interdependencies that includes factors like an absolute reliance on simple bacteria, which allow us to digest our food. We depend on other complex animals, who perform important functions in the world and who are, like us, dependent on intricate webs of energy systems—systems involving tectonic forces, ocean currents, the rising and falling of global temperatures, and many other basic elements.
Without all that complexity—even the catastrophes—we would not be what we are today. When he wrote his great treatises, Darwin was only beginning to grasp these processes—a solid understanding of plate tectonics wouldn’t come for another hundred years—so it’s not surprising that although he realized that life changed over time, he continued to see life as hierarchical. When Darwin was alive, an inordinate number of those puzzle pieces, like plate tectonics, were missing. He was trying to figure out the whole picture with only a few bits of information. Nevertheless, genius that he was, he recognized the essential idea that life ebbs and flows with the passing of time and devoted his whole self to making that case. Imagine what he would have been able to understand had he only known that continents move.
Fortunately for us, over the past 150 years or so, scientists have managed to discover a few more clues to the full picture. There are certainly more out there, and when they are uncovered, our grasp of evolution will become even more fascinating. Darwin saw only the tip of the iceberg, and now we see a few feet below the surface. There’s so much more to understand. I once read an essay written by a scientist at the end of the nineteenth century about the recent discovery of the electron. It’s time, he concluded, for science to close up shop. We now know all there is to know. Then, only a few years later, in 1905, Einstein published E=mc2, providing us with a whole new depth of understanding about the nature of energy.
Darwin knew quite well that his theory was just the start of a fabulous journey, and he might have been delighted to learn that evolution is not about who is “higher” than whom, but about how our roots connect us. Nature forms the foundation for nurture, like the pedestal on which a great piece of sculpture is placed.
Today we know that nature provides the fundamental commonalities that allow us to understand other living things. We understand the expression of fear in a horse’s eyes because we share an evolutionary history with the horse. This doesn’t mean that we are nothing but our biology, which is unfortunately how explanations are sometimes framed by some scientists and scholars who are not quite careful enough with their words. But it does mean that these biologically based commonalities vastly improve our lives, because we can understand the horses and other animals who share our world with us. Without these companions who have traveled with us through time, we’re just floating in space, disconnected.
“Human beings are species-lonely,” the author Thomas McGuane wrote in Some Horses. When I read his sentence, I felt grateful. Someone had finally voiced what those of us with horses have always known: there’s something innate in us, as in horses, that yearns to bond. We must have horses and dogs and cats and other animals in our lives in order for our psyches to function as they should, just as we have to have bacteria in our guts in order to digest food.
Today, science is explaining something about why this is true. For example, cortisol is a hormone common to most animals. Even fish have cortisol, which tells us that it appeared early in vertebrate evolution. High levels of cortisol have long been known to correlate with high levels of stress and with stress-induced illnesses. Now research shows that people who have pets tend to have lower cortisol levels—indicating lower stress levels—than people without pets. People who spend their lives around animals often live longer, happier, healthier lives.
Pleistocene artists must have known that, too, on some level. I realized that when I visited their dwellings and saw their work. In the Spanish caves where people gathered in groups, horses and other animals on the cave walls kept the people company. The artists expressed the essence of these horses—“the rasa of a horse,” to quote the neuroscientist Vilayanur Ramachandran—through simple lines showing the arch of the neck or the distinctive, graceful topline of the horse’s back. It was as though these artists wanted the animals to always be with them, to keep them company.
This is innate. Years ago, in a tent by a river in Zimbabwe, I woke up at first light because the noise from the animals—chuffling hippopotamuses, screaming baboons, singing birds—was louder than earlymorning garbage trucks on a New York City street. The cacophony was overwhelming. But unlike the noise made by city trucks, these noises were comforting, like the extremely loud, overwhelming Freude chorus of Beethoven’s Ninth Symphony. The animals around my tent that morning were performing the ultimate “Ode to Joy,” and it was one that, although new to my ears, I recognized.
Had Darwin managed to see the fruits of his thinking in the twenty-first century, he would have been, I believe, thrilled to learn that the mind of the human is not “superior” to the mind of the horse, but is, rather, complementary.
* * *
What was going on in Lukas’s mind while he was dancing with Karen? We have to be careful here, when asking this question in a scientific manner. In the field of animal cognition, the story of Clever Hans, a horse from the early twentieth century and one of my all-time favorite horses, has become a cautionary tale about not reading too much into the mind of the horse. Clever Hans was a great horse. Like Lukas and Whisper, he managed to lead an interesting life. He and his owner were obsessed with each other. His owner taught the horse to do “math” and frequently exhibited his skills in public. “How much is six plus two?” the owner would ask. Then Hans would tap eight times with his front hoof. He always gave the right answer. He turned out to be equally talented at multiplication and division.
Clever Hans being tested
Hans was famous. Hi
s face was plastered all over the front pages of newspapers worldwide. But, of course, there were people who doubted that Hans really was the genius his owner claimed he was. In response, Hans’s owner agreed to a test. Instead of the owner taking Hans through his mathematical paces, others—strangers to Hans—gave him problems to solve. And still Hans answered correctly.
Then Hans’s questioners hid behind a screen, so that they could test the horse without being seen. Suddenly, Hans could no longer respond. It turned out that Hans, like Lucas, was reading body language: when Hans’s owner and other people asked questions, they moved their heads forward slightly when the horse got to the correct answer. Their body language was subtle and unintentional, yet universal to everyone who tested Hans. Remarkably, Hans was interpreting those tiny head movements. He understood that body language even when the testers were strangers to him. Hans, it seems, knew more about us than we knew about ourselves, at least in this regard.
Sadly, once the truth was known, Hans and his owner fell from grace. Because Hans couldn’t really do math, people dismissed his abilities, disregarding the horse’s obvious intelligence—his ability to understand what humans wanted by studying their behavior.
If Hans’s true talent was overlooked, that was not unusual. Just as Charles Darwin saw evolution in terms of hierarchy, until very recently many of us have thought about intelligence in terms of what humans believe to be intelligent—like the ability to do math. Indeed, animals were not thought by some scientists to possess intelligence at all, but merely to behave according to the simple rules of reward and punishment—simple positive and negative reinforcement. The minds of all animals, including humans, were thought at birth to be blank slates upon which experience wrote. To attribute the ability to think to an animal was said to be just anthropomorphism.
Today we know that’s not true, and that this black-and-white view was a handicap. Once we let go of that belief, we began a renaissance in our understanding of animal minds. For example, in the opening chapter of his groundbreaking book titled, appropriately, Animal Minds, Donald R. Griffin wrote that “conscious thinking may well be a core function of central nervous systems”—a statement that brought him a lot of heat when he first published his book in 1992. Not that Don cared: He was a natural-born revolutionary, a true outlier. His earlier book, The Question of Animal Awareness, published in 1976, suggesting that animals were conscious, was called “subversive” by one opponent, which delighted him. He was never one for conformity.
If he were alive today, he would have enjoyed seeing that his ideas led to an awakening. Researchers curious about animal thinking began constructing scientific experiments that would help us, slowly, penetrate the complexities of how other animals think. Unfortunately, he never addressed the mind of the horse, most likely because there was little extant research on that subject during his lifetime.
I attribute that neglect to two factors. First, during Don’s lifetime, horses, for perhaps the first time in the history of the horse-human partnership, played a very small role in human culture. Cars had replaced horsepower, and horses had come to be seen in many places as luxuries. The invention of tanks and other military equipment meant that horses were no longer used in war. Farmers gave up horse-powered plows for tractors. Because horses were less common, few researchers were interested in them. But the more important factor was the story of Clever Hans. Anyone studying the mind of the horse was laying himself open to the dreaded charge of anthropomorphism.
That’s changed over the last several decades. As the influence of behaviorism has waned and our understanding of evolution has improved, interest in studying the minds of animals has accelerated. Today a small group, based mostly in Europe, has begun to include horses in the array of animals whose ability to think is worthy of research. What these studies reveal in terms of the horse’s intelligence is fascinating.
Of course, some people who are intimately involved with horses take for granted that they are intelligent. But there’s a difference between anecdote and science. When I was young, I recognized that there was something special about Whisper. I was quite proud of his achievements. But those stories were just stories—not methodical investigations into his abilities.
Science often begins with an anecdote: Brian Timney saw his horses staring at hot air balloons in the distance. But then, based on this anecdotal experience, he devised a set of research experiments that revealed a great deal about how horses see. This is now also happening in the field of equine cognition. Some of the findings of these scientists are enlightening.
The Oklahoma research psychologist Sherril Stone decided to find out whether horses could learn about the three-dimensional world in which they lived by looking at a two-dimensional board. Brian Timney had already shown that horses, when looking at lines on a board, are susceptible to the Ponzo illusion—the misreading of line lengths placed on a flat board. Stone took this research one step further.
First she taught several horses to approach a particular shape, like a star or a triangle, shown in two dimensions on a flat board. She put two of these signs up on a wall. If the horse approached the correct sign on the wall, he received a food reward. If the horse approached the other sign, he did not.
Next, Stone made three-dimensional models of those two-dimensional shapes. She found that when the horses were released into a paddock, they went and stood by the three-dimensional shape that looked like what they’d seen two-dimensionally on the board. Most of the horses did pretty well with the task: they stood consistently by the three-dimensional object that resembled the two-dimensional sign they’d learned to associate with food.
I was surprised that horses could transfer what they’d learned from an image to real life. I would have thought such a thing had to be taught, and that the teaching would require a great deal of time.
In the next phase of her experiment, Stone took photos of two human faces and put them on two-dimensional boards. The horses learned to associate food rewards with one face, but not with the other. Then she released the horses into a paddock. The horses approached the person who had the face that they’d learned to associate on the two-dimensional board with food.
They were quite successful at this task, in all cases but one. For some horses, Stone had used photographs of two identical twins. The horses learned to differentiate the photos of the twins, but in a real-life situation, they could not tell one twin from the other.
“I can’t either, most of the time,” Stone told me.
I wondered how the horses would have been able to differentiate between even the photos of the twins. When I studied the faces of the twins in the paper Stone published about her research, I, too, could find slight differences in the photographed faces of the identical twins. But I had to pay close attention. I suspect that in real life I also would have had trouble telling the twins apart.
What parts of the human face were the horses looking at? The last decade of research into our own neural networks has shown that the human brain is littered with groups of neurons that specialize in processing information derived from the faces of others. At least one of these patches of cells is directly connected to the amygdala, which influences our emotional responses to the world around us, according to Kandel. This is why we respond so quickly to emotional expressions.
Do horses have such neurons? “Very likely,” the neurobiologist Hans Hofmann told me, “since all mammals thus far have very similar makeup of their social brains.” If so, are any of those groups of neurons in horses connected to the amygdala, as they are with us? That research has yet to be done.
Of course, research results must be able to be replicated by other scientists, using different study subjects. British researchers Jennifer Wathan and Karen McComb have also looked at how horses respond to photographs. This time, they tested seventy-two horses in order to try to understand what would happen if the test subjects looked not at human faces but at the faces of other horses placed on a two-dimensional board.
First the researchers took a photo of the head of a horse. The horse was paying attention to something that could not be seen in the photo. His eyes and ears were focused on that unseen object. The ears were pointed toward that object, and the horse’s gaze was clearly directed toward that same focal point. They hung this photo on a wall, halfway between two grain buckets placed on the ground. The horse in the photograph appeared to be paying attention to one of these two buckets.
Next, they led a test horse to a spot several feet away from the photo and the two grain buckets. The horse was allowed to approach the photo and grain buckets. As he walked forward, the test horse often stopped and looked at the photo of the horse. Then he usually chose the direction in which the photographed horse seemed to be looking and put his nose in the grain bucket that seemed to be drawing the attention of the photographed horse. This showed that the test horses were taking cues from the horse in the photograph.
But what cues were these horses looking for in the photograph? In the next phase of the study, researchers blindfolded a horse and then photographed him. They also photographed a horse who had had his ears covered with a cloth. When these photos were placed on the wall between the two grain buckets, the study-subject horse wavered when approaching the photo and the grain buckets. He seemed uncertain. His choice of which grain bucket to approach was inconsistent. It didn’t matter whether the photographed horse had either his eyes or his ears covered; the test horse seemed to need to see the whole face of the horse in order to make a decision.
So the research showed that horses rely on cues provided by both the eyes and the ears of other horses. Like the studies of Timney and Stone, it shows that horses can understand two dimensions and apply that understanding to the world around them, but it also confirms that horses are highly social and communicate with each other on a routine basis. They read body language and make decisions based on what they’ve seen. Clever Hans had developed this skill to a very high degree.
The Horse Page 25