Second, it makes no sense to test monkeys on social skills without giving them a chance to express these skills in daily life. They need to be completely familiar with one another for us to investigate how they share food, cooperate, or judge one another’s situation. Kummer understood all this, having started out, like myself, as a primate watcher. In my opinion, anyone who intends to conduct experiments on animal cognition should first spend a couple thousand hours observing the spontaneous behavior of the species in question. Otherwise we get experiments uninformed by natural behavior, which is precisely the approach we should be leaving behind.
Today’s evolutionary cognition is a blend of both schools, taking the best parts of each. It applies the controlled experimental methodology developed by comparative psychology combined with the blind testing that worked so well with Clever Hans, while adopting the rich evolutionary framework and observation techniques of ethology. For many young scientists, it is now immaterial whether we call them comparative psychologists or ethologists, since they integrate concepts and techniques from both. On top of this comes a third major influence, at least for work in the field. The impact of Japanese primatology is not always recognized in the West—which is why I have called it a “silent invasion”—but we routinely name individual animals and track their social careers across multiple generations. This allows us to understand the kinship ties and friendships at the core of group life. Begun by Imanishi right after World War II, this method has become standard in work on long-lived mammals, from dolphins to elephants and primates.
Unbelievably, there was a time when Western professors warned their students away from the Japanese school because naming animals was considered too humanizing. There was of course also the language barrier, which made it hard for Japanese scientists to get heard. Junichiro Itani, Imanishi’s foremost student, was met with disbelief when he toured American universities in 1958 because no one believed that he and his colleagues were able to tell a hundred or more monkeys apart. Monkeys look so much alike that Itani obviously was making things up. He once told me that he was mocked to his face and had no one to defend him except the great American primatological pioneer Ray Carpenter, who did see the value of this approach.47 Nowadays, of course, we know that recognizing a large number of monkeys is possible, and we all do it. Not unlike Lorenz’s emphasis on knowing the whole animal, Imanishi urged us to empathize with the species under study. We need to get under its skin, he said, or as we would nowadays put it, try to enter its Umwelt. This old theme in the study of animal behavior is quite different from the misguided notion of critical distance, which has given us excessive worries about anthropomorphism.
The eventual international embrace of the Japanese approach illustrates something else that we learned from the tale of two schools—ethology and comparative psychology—which is that the initial animosity between divergent approaches can be overcome if we realize that each has something to offer that the other lacks. We may weave them together into a new whole that is stronger than the sum of its parts. The fusing of complementary strands is what makes evolutionary cognition the promising approach it is today. But sadly it took a century of misunderstandings and colliding egos before we got there.
Beewolves
Tinbergen was in tears when I last saw him. It was 1973, the year in which he, Lorenz, and von Frisch were honored with Nobel prizes. He had come to Amsterdam to receive a different medal and give a lecture. Speaking in Dutch, his voice quavering with emotion, he asked what we had done to his country. The magnificent little spot in the dunes where he had studied gulls and terns was no more. Decades earlier, while emigrating aboard a boat to England, he had pointed at the site—the eternal self-rolled cigarette in his hand—predicting that “it will all go, irrevocably.” Years later the place was swallowed up by the expansion of Rotterdam harbor, then the busiest in the world.48
Tinbergen’s lecture reminded me of all the great things he had done, which included animal cognition, even though he never used the term. He had worked on how digger wasps find their nest after a trip away. Also known as beewolves, these wasps capture and paralyze a honeybee, drag it to their nest in the sand (a long burrow), and leave it as a meal for their larvae. Before they go out to hunt for a bee, they make a brief orientation flight to memorize the location of their inconspicuous burrow. Tinbergen put objects around the nest, such as a circle of pinecones, to see what information they used to find it back. He was able to trick the wasps, making them search at the wrong location, by moving his pinecones around.49 His study addressed problem solving tied to a species’ natural history, precisely the topic of evolutionary cognition. The wasps proved very good at this particular task.
Brainier animals have less restricted cognition and often find solutions to novel or unusual problems. The ending of my grapefruit story with the chimpanzees offers a nice demonstration. After releasing the apes onto the island, a number of them passed over the site where we had hidden the fruits under the sand. Only a few small yellow patches were visible. Dandy, a young adult male, hardly slowed down when he ran over the place. Later in the afternoon, however, when all the apes were dozing off in the sun, he made a beeline for the spot. Without hesitation, he dug up the fruits and devoured them at his leisure, which he would never have been able to do had he stopped right when he saw them. He would have lost them to dominant group mates.50
Here we see the entire spectrum of animal cognition, from the specialized navigation of a predatory wasp to the generalized cognition of apes, which allows them to handle a great variety of problems, including novel ones. What struck me most is that Dandy at his first passing didn’t linger for a second. He must have made an instant calculation that deception was going to be his best bet.
3 COGNITIVE RIPPLES
Eureka!
The sunny, breezy Canary Islands are about the last place in the world where one would expect a cognitive revolution, yet this is where it all began. In 1913 the German psychologist Wolfgang K?hler came to Tenerife, off the coast of Africa, to head the Anthropoid Research Station, where he remained until after World War I. Even though rumor has it that his job was to spy on passing military vessels, K?hler devoted most of his attention to a small colony of chimpanzees.
Having eluded indoctrination in the learning theories of his day, K?hler was refreshingly open-minded about animal cognition. Instead of trying to control his animals to seek specific outcomes, he had a wait-and-see attitude. He presented them with simple challenges to find out how they’d meet them. For his most talented chimpanzee, Sultan, he would put a banana out of reach on the ground and offer him sticks that were too short to reach the fruit. Or he would hang a banana high up in the air and spread large wooden boxes around, none of which was tall enough for the purpose. Sultan would first jump or throw things at the banana or drag humans by the hand toward it in the hope that they’d help him out, or at least be willing to serve as a footstool. If this failed, he would sit around for a while without doing anything until he might hit at a sudden solution. He would jump up to put one bamboo stick inside another, making a longer stick. Or he would stack boxes on top of one another so as to build a tower that allowed him to reach the banana. K?hler described this moment as the “aha! experience,” as if a lightbulb had been switched on, not unlike the story of Archimedes, who jumped out of his bath in which he had discovered how to measure the volume of submerged objects, after which he ran naked through the streets of Syracuse, shouting “Eureka!”