That we can’t compete with squirrels and nutcrackers on this task—I even forget where I parked my car—is irrelevant, since our species does not need this kind of memory for survival the way forest animals braving a freezing winter do. We don’t need echolocation to orient ourselves in the dark; nor do we need to correct for the refraction of light between air and water as archerfish do while shooting droplets at insects above the surface. There are lots of wonderful cognitive adaptations out there that we don’t have or need. This is why ranking cognition on a single dimension is a pointless exercise. Cognitive evolution is marked by many peaks of specialization. The ecology of each species is key.
The last century has seen ever more attempts to enter the Umwelt of other species, reflected in book titles such as The Herring Gull’s World, The Soul of the Ape, How Monkeys See the World, Inside a Dog, and Anthill, in which E. O. Wilson, in his inimitable fashion, offers an ant’s-eye view of the social life and epic battles of ants.8 Following in the footsteps of Kafka and Uexküll, we are trying to get under the skin of other species, trying to understand them on their terms. And the more we succeed, the more we discover a natural landscape dotted with magic wells.
Six Blind Men and the Elephant
Cognition research is more about the possible than the impossible. Nevertheless, the scala naturae view has tempted many to conclude that animals lack certain cognitive capacities. We hear abundant claims along the lines of “only humans can do this or that,” referring to anything from looking into the future (only humans think ahead) and being concerned for others (only humans care about the well-being of others) to taking a vacation (only humans know leisure time). The last claim once had me, to my own amazement, debating a philosopher in a Dutch newspaper about the difference between a tourist tanning on the beach and a napping elephant seal. The philosopher considered the two to be radically different.
In fact, I find the best and most enduring claims about human exceptionalism to be the funny ones, such as Mark Twain’s “Man is the only animal that blushes—or needs to.” But, of course, most of these claims are deadly serious and self-congratulatory. The list goes on and on and changes every decade, yet must be treated with suspicion given how hard it is to prove a negative. The credo of experimental science remains that an absence of evidence is not evidence of absence. If we fail to find a capacity in a given species, our first thought ought to be “Did we overlook something?” And the second should be “Did our test fit the species?”
A telling illustration involves gibbons, which were once considered backward primates. Gibbons were presented with problems that required them to choose between various cups, strings, and sticks. In test after test, these primates fared poorly compared to other species. Tool use, for example, was tested by dropping a banana outside their cage and placing a stick nearby. All they had to do to get the banana was pick up the stick to move it closer. Chimpanzees will do so without hesitation, as will many manipulative monkeys. But not gibbons. This was bizarre given that gibbons (also known as “lesser apes”) belong to the same large-brained family as humans and apes.
The gibbon’s hand lacks a fully opposable thumb. It is suited for grasping branches rather than for picking up items from a flat surface. Only when their hand morphology was taken into account did gibbons pass certain intelligence tests. Here a comparison between the hands of a gibbon, a macaque, and a human. After Benjamin Beck (1967).
In the 1960s an American primatologist, Benjamin Beck, took a fresh approach.9 Gibbons are exclusively arboreal. Known as brachiators, they propel themselves through trees by hanging by their arms and hands. Their hands, which have tiny thumbs and elongated fingers, are specialized for this kind of locomotion: gibbon hands act more like hooks than like the versatile grasping and feeling organs of most other primates. Beck, realizing that the gibbon’s Umwelt barely includes the ground level and that its hands make it impossible to pick up objects from a flat surface, redesigned a traditional string-pulling task. Instead of presenting strings lying on a surface, as had been done before, he elevated them to the animal’s shoulder level, making them easier to grasp. Without going into detail—the task required the animal to look carefully at how a string was attached to food—the gibbons solved all the problems quickly and efficiently, demonstrating the same intelligence as other apes. Their earlier poor performance had had more to do with the way they were tested than with their mental powers.
Elephants are another good example. For years, scientists believed them incapable of using tools. The pachyderms failed the same out-of-reach banana test, leaving the stick alone. Their failure could not be attributed to an inability to lift objects from a flat surface, because elephants are ground dwellers and pick up items all the time, sometimes tiny ones. Researchers concluded that they just didn’t get the problem. It occurred to no one that perhaps we, the investigators, didn’t get the elephant. Like the six blind men, we keep turning around and poking the big beast, but we need to remember that, as Werner Heisenberg put it, “what we observe is not nature in itself, but nature exposed to our method of questioning.” Heisenberg, a German physicist, made this observation regarding quantum mechanics, but it holds equally true for explorations of the animal mind.
In contrast to the primate’s hand, the elephant’s grasping organ is also its nose. Elephants use their trunks not only to reach food but also to sniff and touch it. With their unparalleled sense of smell, these animals know exactly what they are going for. But picking up a stick blocks their nasal passages. Even when they bring the stick close to the food, it impedes their feeling and smelling it. It is like sending a blindfolded child out on an Easter egg hunt.
What sort of experiment, then, would do justice to the animal’s special anatomy and abilities?
On a visit to the National Zoo in Washington, D.C., I met Preston Foerder and Diana Reiss, who showed me what Kandula, a young elephant bull, can do when the problem is presented differently. The scientists hung fruit high up above Kandula’s enclosure, just out of his reach. They gave the elephant several sticks and a sturdy square box. Kandula ignored the sticks but, after a while, began kicking the box with his foot. He kicked it many times in a straight line until it was right underneath the fruit. He then stood on the box with his front legs, which enabled him to reach the food with his trunk. An elephant, it turns out, can use tools—if they are the right ones.
Elephants were believed to be inept tool users based on the assumption that they should use their trunk. In a tool task that bypassed the trunk, however, Kandula had no trouble reaching green branches hanging high above his head. He went out of his way to fetch a box to stand on.
As Kandula munched his reward, the investigators explained to me how they had varied the setup, making life more difficult for the elephant. They had put the box in a different section of the yard, out of view, so that when Kandula looked up at the tempting food, he would need to recall the solution while distancing himself from his goal to fetch the tool. Apart from a few large-brained species, such as humans, apes, and dolphins, not many animals will do this, but Kandula did it without hesitation, fetching the box from great distances.10