The Horse
Page 26
* * *
Once a horse has learned something, how long does he remember what he’s learned? The French researcher Carol Sankey has shown that horses remember for long periods of time, and that early experiences may stay with them for quite a while. She has also shown that positive reinforcement is much more effective than negative reinforcement.
Sankey studied two groups of foals who had had minimal contact with humans. One group of foals was taught to stand still on command and given a food reward when they stood quietly. The other group of foals was taught to stand still but did not receive a food reward. Sankey found that the foals who received the food reward learned more quickly and remembered their training better than the foals who did not receive food rewards. She also found that the foals’ positive experiences transformed into a more positive attitude toward humans in general. “Horses are no different from humans,” Sankey wrote. “They behave, learn and memorize better when learning is associated with a positive situation.”
One reason why both horses and humans learn better in positive situations is because placental mammals have social-behavior and reward-behavior neural circuitry with evolutionary roots stretching all the way back to the pre-dinosaur era, suggests Hans Hofmann. When these reward circuits are activated, that memory stays with them.
The discovery of this reward circuit dates back to the 1950s, when researchers found that if rats could press a lever that delivered a small amount of electricity to a certain part of their brains, they would then press the lever over and over again, even to the point of starving to death rather than taking time off to eat. In other words, they became addicted. This center—the nucleus accumbens—is present in all mammals and is involved in many addictions, including human addiction to drugs and alcohol.
The nucleus accumbens is only one part of the reward circuit. Hofmann has studied a second circuit that’s similar, the social behavior circuit. He believes this brain circuitry also evolved long ago. “These social circuits are there even in fish, which also have complex social groups. The circuits have been around a long, long time, although they probably don’t function now the way they did 500 million years ago,” he told me. Hofmann has found that even fish experience some level of bonding and that because of this ancient social network they sometimes even exhibit parental care.
“When you think about it,” Hofmann said, “this isn’t so surprising. All animals face similar challenges and similar opportunities. They have to find mates, find food, defend themselves.”
Then he asked me a question: “Do you think horses are able to bond with humans in ways similar to dogs?”
I considered my answer. Before I started researching this book, I would have said no. Left to their own devices, I would have said, horses would prefer not to be bothered by us.
Now, I said to Hofmann, I was rethinking that point of view.
“I think they probably are like dogs,” Hofmann said. “I’m not a horse person, but I’m an animal behaviorist. I do know that horses form very complex social groups and that domestication of horses wouldn’t have been so successful if horses weren’t able to have so much social cognition.”
The idea that I could have a relationship with a horse somewhat on the level of my relationship with my border collie was beginning to dawn on me. Horses live social lives that are every bit as complex and compelling as the social lives of elephants. I thought about High Tail and her chosen stallion, and about Karen and Lukas, and realized that we have, since the days of the Pleistocene artists, neglected to fully examine the true nature of horses.
* * *
It stands to reason that animals able to form bonds can engage with and learn from each other. But what is the best learning environment for a horse? Sankey’s suggestion that horses learn best through positive reinforcement has been backed up by preliminary research from the behavioral biologist Kathleen Morgan. She wanted to know if, when training miniature horses, a negative (aversive) action was more or less effective than a positive action. She studied two groups of horses: one trained to step sideways by being pushed sideways (negative action), and the other trained to step sideways by being rewarded when the correct behavior was performed. Sankey found that both groups learned the task at about the same speed, but that the horses who received the reward for the correct behavior were more willing to engage with the trainer to learn new tasks later on. Just like Lukas, the miniature horses seemed to enjoy engaging with their humans.
Reward rather than force set the horses up for better long-term learning. “The partnership is different when the animal is being only positively reinforced,” she told me. “We got a better-quality buy-in. It was like putting money in the trust bank: if you have a lot in that trust bank, then when you have to do something that the horse really doesn’t like, like floating teeth,* it might be easier to get a withdrawal from the bank than if you’re already running in the red. We’re investing in the relationship this way because it will pay off later.”
Like Kathleen Morgan, the German ethologist Konstanze Krüger has studied how horses learn, but in Krüger’s case, she has studied natural learning in horses by watching their behavior with each other. Krüger looked at two separate populations of horses—horses stabled in barns and horses allowed free range.
Earlier research seemed to show that horses did not learn by watching each other. This kind of learning is called “social learning.” Krüger thought this had to be wrong. Certainly horses capable of forming strong bonds and of reading body language ought to be able to learn by watching. We know through many studies, including those of Jane Goodall, that African primates learn by watching and thus have what some call “culture”—the transmission of knowledge through generations. A generous body of research shows that this is true of nonmammalian vertebrates like birds, too.
So it made sense to Krüger that horses would also do this. A band of horses would have to learn from others where to find water holes and where to find the best places to graze. Anecdotal tales also suggest this. And as any horse owner knows, some horses watch people open stall doors and then copy the behavior. I know that I didn’t “teach” Whisper how to get water out of a faucet. He had to have watched me use my hand (in his mind, possibly, my hoof) to get water out of that piece of metal, and he tried it, too. Some trainers work with young horses by first exposing them to a more experienced horse doing the same thing.
These are all anecdotal experiences, of course, but Krüger put a scientific face on this question. In one experiment, she trained a horse to follow a human. Then she had another horse stand and watch the first horse follow the human. Horse Number Two learned by watching Horse Number One and followed the same human—but only if Horse Number One was older than Horse Number Two and held a higher status in the horse band. If Horse Number Two, the watching horse, was socially superior to Horse Number One, she found, the observing horse paid no attention.
Age and experience counts, in groups of horses as well as in groups of humans. Other animals do this, too, she told me. “It’s possible to observe something similar in baboons. These animals do not respond to alarm calls from lower animals, but if the alarm call comes from a high-ranking animal, then they’re all up the trees. That’s because the older, more experienced animals have more reliable information.”
“It’s also of evolutionary benefit to build up knowledge from one generation to the next,” Krüger continued. To remove experienced animals from a band or a herd puts the whole group at risk, she said, adding that when people shoot older African elephants, they’re destroying knowledge that’s essential for the survival of the next generation. The same, she said, would be true for bands of horses.
Interested in learning more about how ranking affects horses in a band, Krüger decided to study conflict resolution in horses. She has found that even foals know how to ease tensions among band members by clacking their teeth together in a gesture of appeasement.
“We’ve also got intervention behavior in mares
and in stallions,” she said. “For example, when a stallion from somewhere else gets involved in aggression between two stallions. We’ve found that it’s not always a dominant stallion that intervenes in a conflict and that it’s not necessarily the case that the stallion who intervenes rises in stature.”
Peacemaking among horses—a novel idea. But her story reminded me of the three-way stallion encounter Jason Ransom and I had seen in the Pryor Mountains. I explained the story of the snaking stallion who chased another stallion over the meadow until Duke appeared from below the ridgeline. All that was needed was Duke’s sudden appearance with his stern posture and his beautifully arched neck for the other two stallions to stop fighting. In that case, Duke was a dominant stallion, but, Krüger told me, the peacemaker may not always be the one in charge.
“We can’t put a finger on why some horses do this frequently, while others don’t,” she told me. “It’s a fascinating behavior. Our hypothesis is that we have more-social and less-social animals, pretty much like with people. Some are willing to intervene and regulate and some are not.”
Krüger’s finding is revolutionary, in that stallion behavior is almost always described in simple terms of aggression and dominance. I asked her why, evolutionarily, stallions might get involved in mediating disputes.
“We are down to two explanations,” she answered. “Maybe it’s just that all members benefit from this aggression regulation. Or maybe it’s about the protection of and building up of social bonds.”
* * *
But what about numerical ability? Can horses really understand anything about numbers, or was that just wishful thinking on our part? We now know that some animals—birds and other primates, most notably—may be able to keep track of small numbers. Can horses also do this? Clever Hans wasn’t really able to do math, but Karen Murdock does suggest—anecdotally—that Lukas understands the difference between such numbers as two and four—not just the visual numerals, but the quantity concepts.
The cognitive scientist Claudia Uller, interested in the origins of thinking in animals and humans, decided in 2005 to celebrate the centennial of the unmasking of Clever Hans by daring to begin to tackle the problem of horses and numbers.
“We adapted a task originally devised to be done with infants,” she told me, “so that we could see whether horses were as sensitive to numbers as human babies. Babies are not only perceiving these things, but are keeping these representations in their memory. Others have claimed the same kinds of things for other animals. That’s the theoretical idea for the horse experiments—we wanted to show this for horses. To our knowledge, it was the first time that we were actually showing numerical representations in horses.”
Uller and a graduate student, Jennifer Lewis, showed horses two plastic apples and three plastic apples. The apples were plastic so that researchers could be sure that horses weren’t using their noses to solve the problem. (We assume that the horse’s ability to detect smells is better than our own, but as the French neuroscientist Michel-Antoine Leblanc explains in The Mind of the Horse, scientific research in this area is sparse.) The horses were allowed to watch while researchers put the group of two apples in one bucket. They placed the group of three apples in a second bucket. Both buckets were opaque, so the horses could not see the apples once they were placed inside. To get the apples, the horses had to remember which bucket held the greater number of apples.
Uller and Lewis found that most horses approached the bucket with three apples rather than the bucket with two apples. It’s important to understand that this experiment was not an experiment that showed that horses could learn the difference between the two numbers. Horses had to understand innately the difference between two and three.
“You’re testing an ability that is spontaneously available. There is no training at all. No learning. Each horse gets only one test, one trial. The important thing about this experiment is that the horses had to keep the two numbers in their memory. It’s a quite sophisticated thinking process,” Uller said. “This is particularly interesting because ‘number’ is an abstract ability. It’s not like knowing the difference between an apple and an orange. Number is in the mind: The ‘threeness’ of a set of apples. You build a representation in your mind of ‘threeness.’ This shows that horses can think abstractly, and they do not depend on language to do so.”
This is just a preliminary study, which needs to be confirmed, but it falls into line with other recent studies that show that our ability to understand and communicate with animals is based in part on abilities that may have evolved quite early in the history of life.
Beyond the details of gross brain anatomy, we don’t know much about the similarities and differences between human and horse brains, but we are learning a few facts about the similarities between the brains of dogs and humans, which tells us something about why we are able to work together so well. The Hungarian researcher Attila Andics and his colleagues taught eleven dogs to lie still in an MRI scanner. Researchers watched which parts of the dogs’ brains responded when the dogs heard other dogs bark, and which parts responded when the dogs heard people talk. Then they put humans in an MRI and ran the experiment in reverse, watching which parts of the human brain responded when they heard other people talking and when they heard dogs barking.
They found that certain voice-sensitive areas in the brain lit up in dogs as well as in humans when they heard communication sounds. Dogs responded more strongly to the sounds made by other dogs, but they also responded strongly to human speech. Humans responded most strongly to the sounds made by other humans, but also responded to the sounds made by dogs. Researchers suggest that those voice-sensitive areas are also likely present in the brains of other mammals.
Horses have yet to be studied this way, but I’m holding out hope. It would be fascinating to learn the details of what might be going on in horses’ brains when we talk to them. Most horse owners will tell you that horses respond to the sounds other horses make and to the sounds made by human voices, and also that horses can tell one human voice from another. But that’s just barn talk.
Now the British researcher Leanne Proops and her colleagues have confirmed in behavioral experiments that horses do indeed connect the “voices” of individual horses with the horses themselves. She led one member of a band of horses up to and then away from a test horse. When the horse being led could no longer be seen by the test horse, she played a recording of the voice of an unfamiliar horse. The test horse paid close attention to the unexpected call of the strange horse, and less attention to the sound of the familiar horse who had just passed by. The call of the strange horse violated the expectations of the test horse, Proops wrote. Later, she found that horses recognized and responded to their owners’ voices, but not to the voices of strangers.
To horse owners, the results of these studies might seem so obvious as to make them not worth doing. But as I’ve mentioned, the scientific study of the thinking abilities of horses has been off-limits for quite a long time. Because of the Clever Hans stigma, we are only now beginning at the beginning. Each of these small studies is helping to build a foundation for further work. And I suspect that some of this research may reveal that horses spend time with us not just because we have the food and the water—but because, sometimes, they just want to be with us.
I think they enjoy the companionship—the partnership works both ways.
* * *
When I was in Vienna attending the wild-horse conference where I met Jason Ransom and Laura Lagos, I visited the Spanish Riding School, where the famous Lipizzan horses have been trained for hundreds of years. It was there that I interviewed Herwig Radnetter, one of the school’s riders.
I’ve always loved these horses. As a small child, I was fortunate enough to see them perform in Madison Square Garden, and later I was allowed to “ride” one. (Well … actually … to sit while someone else led the horse around.) Lipizzans originated in Spain and were introduced to Vienna by the House o
f Hapsburg. For hundreds of years, they have been pampered like princes. The bedding in their stalls is clean enough to sleep on (at least, I would), and the horses have their own personal grooms who check on them constantly.
Today they hold the status of a living European art treasure, as revered as the Parthenon or the Mona Lisa. At the end of World War II, though, the Nazis and the Soviets nearly destroyed the breed. The horses were only saved because of the heroism of Alois Podhajsky, then in charge of caring for the horses, and of several other Viennese and German men who willingly put their lives in danger to get the stallions out of Vienna before they were killed.
The horses also owe their survival to the bullheaded determination of General George S. Patton, then commander of the Third U.S. Army and a devoted equestrian. Patton ordered Colonel Charles Hancock Reed and his men to rescue the horses in an exercise that came to be known as “Operation Cowboy.” A fictionalized version of this tale can be seen in the 1963 film Miracle of the White Stallions.
There has always been a sense of magic attached to these ethereal animals, but the Disney movie increased their glamour. The first time I saw the horses in Vienna, a long line of them were being led, groom by groom, across a public street from their stables to their performing arena. The crowd on the street stopped, awestruck. One woman reached out and touched a stallion. The horse kicked out, and a groom severely reprimanded the woman. She should not have done it. But I understand why she did. Their liquid eyes are irresistible. The stallions are so otherworldly that it seems as though if you touch them, they’ll disappear.
During my interview with him, I asked Radnetter about his involvement with the horses. He explained that when a new, young rider begins his education at the riding school, he is matched with his own set of three young horses. The riders and their horses then undergo a grueling training routine that may last for four or five years. Many of the riders who begin the program drop out after a year or so. The training and discipline are rigorous.