Are We Smart Enough to Know How Smart Animals Are? (26 page)

Even though
Chimpanzee Politics
opened a new agenda for research while introducing Machiavelli’s thinking to primatology, I was never quite happy with “Machiavellian intelligence” as a popular label for this field.
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This term implies an end-justifies-the-means manipulation of others, ignoring a vast amount of social knowledge and understanding that has nothing to do with one-upmanship. When a female chimpanzee resolves a fight between two juveniles over a leafy branch by breaking it into two and handing each youngster a piece, or when an adult male chimpanzee helps an injured, limping mother by picking up her offspring to carry it for her, we are dealing with impressive social skills that don’t fit the “Machiavellian” label. This cynical identifier made sense a few decades ago, when all animal (including human) life was customarily depicted as competitive, nasty, and selfish, but over time my own interests have drifted into the opposite direction. I have devoted most of my research to the exploration of empathy and cooperation. The exploitation of others, by using them as “social tools,” remains a great topic and is an undeniable aspect of primate sociality, but it is too narrow a focus for the field of social cognition as a whole. Caring relationships, the maintenance of bonds, and attempts to keep the peace are equally worthy of attention.

The intelligence required to effectively deal with social networks may explain why the primate order underwent its remarkable brain expansion. Primates have exceptionally large brains. Dubbed the
Social Brain Hypothesis
by British zoologist Robin Dunbar, the connection with sociality is supported by a relation between a primate’s brain size and its typical group size. Primates that live in larger groups generally have larger brains. I always find it hard, though, to separate social and technical intelligence, since many big-brained species are strong in both domains. Even species that hardly handle any tools in the wild, such as rooks and bonobos, may be quite good at it in captivity. It remains true, though, that social challenges have been neglected for too long in discussions of cognitive evolution, which tend to focus on interactions with the environment. Given how all-important social problem solving is in the lives of our subjects, primatologists have been right to amend this view.
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Triadic Awareness

Siamangs—large black members of the gibbon family—swing high up in the tallest trees of the Asian jungle. Every morning, the male and female burst into spectacular duets. Their song begins with a few loud whoops, which gradually build into ever louder, more elaborate sequences. Amplified by balloonlike throat sacs, the sound carries far and wide. I have heard them in Indonesia, where the whole forest echoed with their sound. The siamangs listen to one another during breaks. Whereas most territorial animals need only to know where their boundaries run and how strong and healthy their neighbors are, siamangs face the added complexity that territories are jointly defended by pairs. This means that pair-bonds matter. Troubled pairs will be weak defenders, while bonded pairs will be strong ones. Since the song of a pair reflects their marriage, the more beautiful it is, the more their neighbors realize not to mess with them. A close-harmony duet communicates not only “stay out!” but also “we’re one!” If a pair duets poorly, on the other hand, uttering discordant vocalizations that interrupt one another, neighbors hear an opportunity to move in and exploit the pair’s troubled relationship.
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To understand how others relate to one another is a basic social skill that is even more important for group-living animals. They deal with a far greater variety than the siamang. In a baboon or macaque troop, for example, a female’s rank in the hierarchy is almost entirely decided by the family from which she hails. Owing to a tight network of friends and kin, no female escapes the rules of the matrilineal order according to which daughters born to high-ranking mothers will themselves become high-ranking, while daughters from families at the bottom will also end up at the bottom. As soon as one female attacks another, third parties move in to defend one or the other so as to reinforce the existing kinship system. The youngest members of the top families know this all too well. Born with a silver spoon in their mouth, they freely provoke fights with everyone around, knowing that even the biggest, meanest female of a lower clan will not be allowed to assert herself against them. The youngster’s screams will mobilize her powerful mother and sisters. In fact, it has been shown that screams sound different depending on the kind of opponent a monkey confronts. Thus, it is immediately clear to the entire troop whether a noisy fight fits or violates the established order.
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The social knowledge of wild monkeys has been tested by playing the distress calls of a juvenile from a loudspeaker hidden in the bushes at a moment when the juvenile itself is out of sight. Hearing this sound, nearby adults not only look in the direction of the speaker but also peek at the juvenile’s mother. They recognize the juvenile’s voice and seem to connect it with its mother, perhaps wondering what she is going to do about the trouble her offspring is in.
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The same sort of social knowledge can be seen at more spontaneous moments, when a juvenile female picks up an infant that is unsteadily walking about, only to carry it back to its mother, which means that she knows which female the infant belongs to.

In white-faced capuchin monkeys, the American anthropologist Susan Perry analyzed how individuals form coalitions during fights. Having followed these hyperactive monkeys for over two decades, Susan knows them all by name and life history. During a visit to her field site in Costa Rica, I saw the characteristic coalition stance firsthand. Known as the
overlord
, two monkeys threaten a third with stares and wide-open mouths, one leaning on top of the other. Their opponent thus faces an intimidating display of two monkeys wrapped into one, with both threatening heads stacked on top of each other. Comparing these coalitions with known social ties, Susan found that capuchins preferentially recruit friends who are dominant over their opponent. This by itself is rather logical, but she also found that instead of seeking the support of their best buddies, they specifically recruit those who are closer to themselves than to their opponent. They seem to realize that there is no point appealing to their opponent’s buddies. This tactic, too, requires triadic awareness.
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Two white-faced capuchin monkeys adopt an “overlord” position, so that their adversary is confronted by two threatening faces and sets of teeth at once.

Capuchins solicit support by abruptly jerking their heads back and forth between a potential supporter and their adversary, a behavior known as
headflagging
, which is also used against danger, such as a snake. In fact, these monkeys threaten everything they don’t like, a tendency sometimes used to manipulate attention. Susan once observed the following deceptive sequence:

Pursued by a coalition of three higher-ranking males, Guapo suddenly stopped in his tracks and began to produce frantic snake alarm calls while looking at the ground. I was standing by him and could plainly see that there was nothing there but bare ground. He headflagged to Curmudgeon [one of his enemies] for support against the imaginary snake. Guapo’s pursuers stopped short and stood up on their hind legs to see if there was a snake. After cautious inspection, they once again began threatening Guapo. Switching tactics he glanced up at a passing magpie jay (a nonmenacing bird) and did three bird alarms in rapid succession—calls that are usually reserved for large raptors and owls. Guapo’s opponents looked up, saw that it was not a dangerous bird, and again resumed threatening Guapo. He reverted to the snake alarm call tactic once again vehemently bouncing at the bare patch of ground, threatening the “snake” vocally. Although Curmudgeon continued to glare at Guapo for a bit longer, the rest of the group stopped threatening him, and he was able to resume foraging for insects, moving slowly and nonchalantly towards Curmudgeon while occasionally casting a furtive glance in his direction.
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While such observations suggest but cannot prove high intelligence, there is an urgent need for information on the cognition of wild primates. Fieldworkers are finding ingenious ways to collect it. In Budongo Forest, in Uganda, for example, Katie Slocombe and Klaus Zuberbühler set out to record the screams of chimpanzees under threat or attack. These loud vocalizations serve to recruit aid, which prompted the scientists to see if the acoustics of screams depend on the audience. Given the dispersed lives of wild chimpanzees, only individuals who are within earshot—the audience—are likely to provide aid to a screaming victim. In addition to finding that the intensity of the calls reflected the intensity of the attack, the scientists noted a subtle deception encoded in them. Chimpanzee victims apparently exaggerate their screams (making the attack sound more severe than it truly is), provided their audience includes individuals that outrank their attacker. In other words, whenever the big bosses are around, chimp victims scream bloody murder. Their vocal distortion of the truth suggests precise knowledge of their opponent’s status relative to everyone else.
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More evidence that primates know one another’s relationships comes from the way they classify others based on family membership. Some studies have explored their tendency to
redirect
aggression. Recipients of aggression often look for a scapegoat, not unlike the way people who get reprimanded at work may come home to maltreat their spouse and children. Given their strict hierarchies, macaques are a prime example. As soon as one of these monkeys gets threatened or chased, it will threaten or chase somebody else, always an easy target. Redirected hostility thus travels down the pecking order. Remarkably, redirecting monkeys prefer to target the family of the original aggressor. One monkey will be attacked by a high-ranking individual, then look around to spot a younger, less powerful member of her attacker’s family to take her tensions out on this poor soul. This way redirection resembles revenge, since it makes the family of the instigator pay.
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The same knowledge of family relations also serves more constructive purposes, such as when after a fight between two monkeys of different families, tensions are resolved by
other
members of the same families. Thus, if play between two juveniles turns into a screaming fight, their mothers may get together to make up for their children. It is an ingenious system, but again it requires every monkey to know to which family every other monkey belongs.
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Categorizing others into families may be a case of
stimulus equivalence
, as proposed by the late Ronald Schusterman, an American marine mammal specialist. Ron kept the strangest and most delightful animal laboratory that I have ever set a slippery foot in, since it consisted of not much more than an outdoor swimming pool in sunny Santa Cruz, California. It was the ultimate wet lab. To the side of the pool stood a few wooden panels on which symbols could be mounted for his sea lions. The animals swam in the pool, racing around faster than any human ever could, only to jump out for a few seconds and touch a symbol with their wet noses. Ron’s star performer was his favorite pinniped, named Rio. If Rio made the right choice, a fish would be thrown at her, and she’d dive right back into the pool. She did all this in one fluid movement, catching the fish while sliding back into the water, reflecting perfect coordination between experimenter and subject. Ron explained that most tests were too simple for Rio, resulting in her getting bored and losing her concentration. Making errors, she’d get mad at Ron for not giving her enough fish and angrily toss all her plastic toys out of the pool.

Rio had learned to associate arbitrary symbols. She’d first learn that symbol A belongs with B, then that B belongs with C, and so on. After rewarding her for making the right connections, Ron would surprise her with a brand-new combination, such as A and C. If A and B are equivalent as well as B and C, then A and C must be equivalent, too. Would Rio extrapolate from the previous associations, and group A, B, and C together? She did, applying this logic to combinations that she had never encountered before. Ron saw this as the prototype of how animals may mentally group individuals together, such as families or cliques.
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We do the same: if you learned to connect me first with one of my brothers, then also with another one (I have five!), you should also group those two brothers together in the same family even if you have never encountered them together. Equivalence learning makes for quick and efficient categorization.

Ron went further, speculating about other unseen connections. For example, chimpanzee males have been known to angrily attack and destroy the empty night nests that rival males have left behind in trees at the border of their territory. Unable to attack the enemy itself, the next best target is apparently a nest that they have built. It reminds me of a time in the Netherlands, when owners of black Suzuki Swifts had a tough time. They suffered frequent nasty remarks from people and worse, such as intentional damage to their cars. This situation arose after someone with murderous intentions had driven a black Suzuki Swift into a festive crowd on Queen’s Day, killing eight people. The car itself was obviously not at fault, but humans are quick to connect the dots. A hated action turned a specific car brand into a hated object. It all boiled down to stimulus equivalence.