Are We Smart Enough to Know How Smart Animals Are? (27 page)

Knowing as we do the spontaneous use of triadic awareness, the next question is how it is acquired. To find out, we need experiments. Is it enough for animals to just watch others? In one study, the French psychologist Dalila Bovet rewarded rhesus monkeys at Georgia State University for identifying the dominant monkey in a video. The observing monkeys didn’t know the individuals they were watching and had to judge their relationship purely on the basis of behavior. For example, one monkey in the video would chase another, after which the observer would be trained to select the dominant one (the one who had done the chasing) on a freeze frame of the scene. After learning to do this, the observing monkeys generalized to behaviors that didn’t look like chasing but also indicated dominance. Subordinate rhesus monkeys, for example, communicate their position to the dominant by baring their teeth in a wide grin. Bovet showed videos in which this signal was being exchanged. Even though these scenes were new to the observing monkeys, they correctly picked the dominant party. The conclusion was that they have a concept of rank and are quick to evaluate the status of unknown individuals on the basis of how they interact with others.
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Ravens may show a similar understanding, as evidenced by their reactions to vocalizations played over a loudspeaker. Ravens recognize one another’s voices and pay close attention to dominant and subordinate calls. But then the playbacks were manipulated to make it sound as if a dominant individual had turned submissive. Hearing evidence of a brewing overthrow, the ravens would stop what they were doing and listen while showing signs of distress. They were most upset by rank reversals among members of their own sex in their own group, but they reacted also to status reversals between ravens in an adjacent aviary. The investigators concluded that ravens have a concept of status that goes beyond their own position. They know how others typically interact and are alarmed by deviations from this pattern.
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In a related question, I have always wondered if captive chimpanzees evaluate status differences among the people around them. I once worked at a zoo with a demanding director who would occasionally visit the facilities and order everyone around, pointing out problems, saying this needed to be cleaned, and that needed to be moved, and so on. Showing typical alpha conduct, he kept everyone on their toes, as a good director should. Even though the chimps rarely interacted with him—he never fed them or talked to them—they picked up on this behavior. They treated this man with the utmost respect, greeting him with submissive grunts from a great distance (which they didn’t do for anyone else) as if they realized,
Here comes the boss, the one everyone around here is nervous about.

It’s not just in relation to dominance that chimpanzees make such judgments. One of the best illustrations of their triadic awareness occurs in mediated conflict resolution. After a fight between male combatants, a third party may induce them to make peace. Interestingly, it’s only female chimps who do so, and only the highest-ranking ones among them. They step in when two male rivals fail to reconcile. The male rivals may be sitting near each other and avoiding eye contact, unable or unwilling to make the first move. If a third male were to approach, even to make peace, he’d be perceived as a party to the conflict. Male chimps form alliances all the time, so their presence is never neutral.

This is where the older females come in. The matriarch of the Arnhem colony, Mama, was the mediator par excellence: no male would ignore her or carelessly start a fight that might incur her wrath. She would approach one of the males and groom him for a while, then slowly walk toward his rival while being followed by the first. She would look around to check on the first and return to tug at his arm if he was reluctant. Then she’d sit down next to the second male, while both males would groom her, one on each side. Finally Mama would slip away from the scene, and the males would pant, splutter, and smack more loudly than before—sounds that signal grooming enthusiasm; but by then they would of course be grooming each other.

In other chimpanzee colonies, too, I have seen old females reduce male tensions. It is a risky affair (the males are obviously in a grumpy mood), which is why younger females, instead of trying to mediate themselves, encourage others to do so. They approach the top female while looking around at the males who are refusing to make up. This way, they try to get something going that they can’t accomplish safely by themselves. Such behavior demonstrates how much chimpanzees know about the social relationships of others, such as what has happened between the rival males, what has to be done to restore harmony, and who will be the best one to undertake this mission. It is the sort of knowledge that we take for granted in our own species, but without it animal social life could never have reached its known complexity.

Proof in the Pudding

While cleaning out the old library at the Yerkes Primate Center, we unearthed forgotten treasures. One was the old wooden desk of Robert Yerkes, which is now my personal desk. The other was a film that probably had not been looked at for half a century. It took us a while to find the right projector, but it was worth the trouble. Lacking sound, the film had written titles inserted in between poor-quality black-and-white scenes. It featured two young chimpanzees working together on a task. In true slapstick style, befitting the movie’s flickering format, one of the chimps would slap the other on her back every time her dedication flagged. I have shown a digitized version to many audiences, causing much laughter in recognition of the humanlike encouragements. People are quick to grasp the movie’s essence: apes have a solid understanding of the advantages of cooperation.

The experiment was run in the 1930s by Meredith Crawford, a student of Yerkes.
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We see two juveniles, Bula and Bimba, pulling at ropes attached to a heavy box outside their cage. Food has been placed on the box, which is too heavy for one of them to pull in alone. The synchronized pulling by Bula and Bimba is remarkable. They do so in four or five bursts, so well coordinated that you’d almost think they were counting—“one, two, three … pull!”—but of course they are not. In a second phase, Bula has been fed so much that her motivation has evaporated, and her performance is lackluster. Bimba solicits her every now and then, poking her or pushing her hand toward the rope. Once they have successfully brought the box within reach, Bula barely collects any food, leaving it all to Bimba. Why did Bula work so hard with so little interest in the payoff? The likely answer is reciprocity. These two chimps know each other and probably live together, so that every favor they do for each other will likely be repaid. They are buddies, and buddies help each other out.

This pioneering study contains all the ingredients later expanded upon by more rigorous research. The
cooperative pulling paradigm
, as it is known, has been applied to monkeys, hyenas, parrots, rooks, elephants, and so on. The pulling is less successful if the partners are prevented from seeing each other, so success rests on true coordination. It is not as if the two individuals pull at random and, by luck, happen to pull together.
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Furthermore, primates prefer partners who cooperate eagerly and are tolerant enough to share the prize.
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They also understand that a partner’s labor requires repayment. Capuchin monkeys, for example, seem to appreciate each other’s effort in that they share more food with a partner who has helped them obtain it than with one whose help went unneeded.
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Given all this evidence, one wonders why the social sciences in recent years have settled on the curious idea that human cooperation represents a “huge anomaly” in the natural realm.
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It has become commonplace to assert that only humans truly understand how cooperation works or know how to handle competition and freeloading. Animal cooperation is presented as mostly based on kinship, as if mammals were social insects. This idea was quickly disproven when fieldworkers analyzed DNA extracted from the feces of wild chimpanzees, which allowed them to determine genetic relatedness. They concluded that the vast majority of mutual aid in the forest occurs between unrelated apes.
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Captive studies have shown that even strangers—primates who didn’t know each other before they were put together—can be enticed to share food or exchange favors.
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Despite these findings, the human uniqueness meme keeps stubbornly replicating. Are its proponents oblivious to the rampant, varied, and massive cooperation found in nature? I just attended a conference on Collective Behavior: From Cells to Societies, which addressed the extraordinary ways in which single cells, organisms, and entire species realize goals together.
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Our best theories about the evolution of cooperation stem from the study of animal behavior. Summarizing these ideas in his 1975 book
Sociobiology
, E. O. Wilson helped launch the evolutionary approach to human behavior.
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Excitement about Wilson’s grand synthesis seems to have faded, though. Perhaps it was too sweeping and inclusive for disciplines that consider humans in isolation. Chimpanzees in particular are nowadays often depicted as so aggressive and competitive that they can’t be truly cooperative. If this applies to our closest relatives, so the thinking goes, we can justifiably ignore the rest of the animal kingdom. One prominent advocate of this position, the American psychologist Michael Tomasello, extensively compared children and apes, which has led him to conclude that our species is the only one capable of shared intentions in relation to common goals. He once condensed his view in the catchy statement “It is inconceivable that you would ever see two chimpanzees carrying a log together.”
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At Burgers’ Zoo, live trees are surrounded by electrified wire, yet the chimps manage to get into them anyway. They break long branches out of dead trees and carry them to a live one, where one of them holds the branch steady while another scales it.

This is quite an assertion, given Emil Menzel’s photographed and filmed sequences of juvenile apes recruiting one another to collectively prop a heavy pole up against the wall of their enclosure in order to get out.
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I have regularly seen chimps use long sticks as ladders to get across hot wire surrounding live beech trees; one chimp holds the stick while another scales it to reach fresh leaves without getting shocked. We have also videotaped two adolescent females who regularly tried to reach the window of my office, which overlooks the chimp compound at the Yerkes Field Station. Both females would exchange hand gestures while moving a heavy plastic drum right underneath my window. One ape would jump onto the drum, after which the other would climb on top of her and stand on her shoulders. The two females would then synchronously bob up and down like a giant spring; the one standing on top would reach for my window every time she came close. Well synchronized and clearly of the same mind, these females played this game often in alternating roles. Since they never succeeded, their common goal was largely imaginary.

Literally carrying a log together may not be part of these efforts, but this behavior is trained for all the time in Asian elephants. Until recently, the forest industry in Southeast Asia employed elephants as beasts of burden; now they are rarely used for this purpose anymore, but they still demonstrate their skills for tourists. At the Elephant Conservation Center near Chiang Mai, in Thailand, two tall adolescent bulls will effortlessly pick up a long log with their tusks, each standing on one end, draping their trunks over the log to keep it from rolling off. Then they will walk in perfect unison several meters apart, with the log between them, while the two mahouts on their necks sit chatting and laughing and looking around. They are most certainly not directing every move.

Training is obviously part of this picture, but one cannot train any animal to be so coordinated. One can train dolphins to jump synchronously because they do so in the wild, and one can teach horses to run together at the same pace because wild horses do the same. Trainers build on natural abilities. Obviously, if one elephant were to walk slightly faster than the other while carrying the log, or hold it at the wrong height, the whole enterprise would quickly unravel. The task requires step-by-step harmonization of rhythm and movement by the bulls themselves. They have moved from an “I” identity (I perform this task) to a “we” identity (we do this together), which is the hallmark of collective action. They end their performance by lowering the log together, moving it from their tusks into their trunks and then slowly to the ground. They set the heaviest log down on a pile without a single sound, impeccably coordinated.

When Josh Plotnik tested elephants on the cooperative pulling paradigm, he found a solid understanding for the need to synchronize.
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Teamwork is even more typical of group hunters, such as humpback whales, which blow hundreds of bubbles around a school of fish; the column of bubbles traps the fish like a net. The whales act together to make the column tighter and tighter, until several of them surface through its center with mouths wide open to swallow the bounty. Orcas go even further, in an action so astonishingly well coordinated that few species, including humans, would be able to match it. When orcas along the Antarctic Peninsula spot a seal on an ice floe, they reposition the floe. It takes lots of hard work, but they push it out into open water. Then four or five whales line up side by side, acting like one giant whale. They rapidly swim in perfect unison toward the floe, creating a huge wave that washes off the unlucky seal. We don’t know how the killer whales agree on the lineup or how they synchronize their actions, but they must be communicating about it before making their move. It is not entirely clear why they do it, because even though the orcas afterward carry the seal around, they often end up releasing it. One seal was deposited back onto a different ice floe to live another day.
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