The Origin of Humankind (17 page)

What begins as a conflict between two individuals quickly widens to include friends and relatives, and may be influenced by recent, similar bouts of aggression. “Not only must monkeys predict one another’s behavior, but they must assess one another’s relationship,” Cheney and Seyfarth explain. “A monkey confronted with all this non-random turmoil cannot be content with learning simply who’s dominant or subordinate to herself; she must also know who’s allied to whom and who’s likely to aid an opponent.” The mental exigencies of monitoring social alliances are the key to a paradox in primatology, argues Nicholas Humphrey, a psychologist at the University of Cambridge.

The paradox is this: “It has repeatedly been demonstrated in the artificial situations of the laboratory that the anthropoid apes possess impressive powers of creative reasoning,” explains Humphrey, “yet these feats of intelligence simply do not have any parallels in the behavior of the same animals in their natural environment. I have yet to hear of any example from the field of a chimpanzee . . . using his full capacity for inferential reasoning in the solution of a biologically relevant practical problem.” The same might be said of humans, comments Humphrey. Suppose, for example, Einstein were to be observed as primatologists observe chimpanzees, through a pair of field glasses. He would see flashes of genius from the great man only rarely. “He did not use [his genius], for he did not
need
to use it, in the common world of practical affairs.”

Either natural selection has been profligate in making primates—including humans—smarter than they really need to be, or their daily life is more intellectually demanding than it appears to the outside observer. Humphrey came to believe that the second of these alternatives is correct: specifically, that the social nexus of primate life presents a sharp intellectual challenge. The primary role of creative intellect, he suggests, is “to keep society together.”

Primatologists now know that the network of alliances within primate troops is extremely complex. Learning the intricacies of such a network, as individuals must if they are to succeed, is difficult enough. But the task is made vastly harder by the constant shifting of alliances, as individuals constantly seek to improve their political power. Always looking out for their own best interests, and for the interests of their closest relatives, individuals may sometimes find it advantageous to break existing alliances and form new ones, perhaps even with previous rivals. Troop members therefore find themselves in the midst of changing patterns of alliances, and a keen intellect is demanded in playing the changing game of what Humphrey refers to as social chess.

Players of social chess have to be more skillful than players of the ancient board game, because not only do the pieces unpredictably change identity—knights becoming bishops, pawns becoming castles, and so on—but also allies occasionally switch sides and become the enemy. Players of social chess must be constantly alert, on the lookout for potential advantage, watchful for unexpected disadvantage. How do they do it?

The challenge for individuals in primate societies is to be able to predict the behavior of others. One way would be for individuals to have a huge mental bank in their brains, which stored every possible action of their fellow troop members and their own appropriate responses. This is how the powerful computer program Deep Thought achieves Grand Master status at chess. However, computers are vastly faster than living brains are at sifting through all possible combinations for any particular set of circumstances. Some other means is required. If, for example, individuals were able to monitor their own behavior, rather than merely operate as computerlike automatons, then they would develop a heuristic sense of what to do under certain circumstances. By extrapolation, they might then be able to predict the behavior of others under the same circumstances. This monitoring ability, which Humphrey calls an Inner Eye, is one definition of consciousness, and it would confer considerable evolutionary advantage in those individuals that possessed it.

Once consciousness was established, there was no going back, for individuals less well endowed would be at a disadvantage. Similarly, those with a slight edge would be further favored. An arms race would ensue, driving the process ever onward, boosting intelligence and sharpening self-awareness. As the Inner Eye became ever more observant, inexorably there would emerge a real sense of self, a reflective consciousness, an Inner I.

The hypothesis, which was part of the development of the social intelligence hypothesis, attracted a lot of interest and support. In a review of primate studies, published in 1986 in
Science
, Cheney, Seyfarth, and Barbara Smuts noted the importance of intelligence in social contexts, as compared with its importance in meeting the demands of technology. And Robin Dunbar examined the differing amounts of cerebral cortex—the “thinking” part of the brain—in various species of primate. He discovered that those species that lived in large groups, and therefore faced the more complex games of social chess, had the most extensive cerebral cortex. “This is consistent with the social intelligence hypothesis,” he concluded.

Two lines of evidence have been important in the revolution in the understanding of animal behavior—a revolution that eroded the behaviorist dogma that animals don’t have minds. One was a pioneering set of experiments designed to detect self-awareness—that is, signs of self-recognition—in animals other than humans. The second involved looking for signs of tactical deception in primates in their natural habitat.

An experience as private as consciousness is frustratingly beyond the usual tools of the experimental psychologist. This may be one reason that many researchers have shied away from the notion of mind and consciousness in nonhuman animals. In the late 1960s, however, Gordon Gallup, a psychologist at the State University of New York, Albany, devised a test of the sense of self: the mirror test. If an animal were able to recognize its reflection in a mirror as “self,” then it could be said to possess an awareness of self, or consciousness. Pet owners know that cats and dogs react to their image in a mirror, but often they treat it as that of another individual whose behavior very soon becomes puzzling and boring. (Nevertheless, those same pet owners will swear that their cat or dog is self-aware.)

The experiment—which Gallup dreamed up one morning while shaving—called for familiarizing the animal with the mirror and then marking the animal’s forehead with a red spot. If the animal saw the reflection as just another individual, it might wonder about the curious red spot and might even touch the mirror. But if the animal realized that the reflection was of itself, it would probably touch the spot on its own body. The first time Gallup tried the experiment with a chimp, the animal acted as if it knew that the reflection was its own; it touched the red spot on its forehead. Gallup’s report of the experiment, published in a 1970 article in
Science
, was a milestone in our understanding of animal minds, and psychologists wondered how widespread self-recognition would prove to be.

Not very, is the answer. Orangutans passed the mirror test, but, surprisingly, gorillas did not. In less formal situations, some observers claim to have seen gorillas use mirrors as if they recognized their own image, which they take to indicate a sense of self in these animals. A mental Rubicon, with self-awareness on one side and its absence on the other, would make sense if the self-aware side included humans and the great apes, with the rest of the primates and other animals on the other. However, some primatologists considered this too exclusive a division, given their observations of the complex social lives of many monkey species. A test of this exclusivity emerged recently, that of “tactical deception.”

Andrew Whiten and Richard Byrne, of the University of St. Andrews in Scotland, coined this term, which they define as “an individual’s capacity to use an ‘honest act’ from his normal repertoire in a different context, such that even familiar individuals are misled.” In other words, one animal intentionally lies to another. In order to be able to deceive intentionally, an animal must have a sense of how its actions appear to another individual. Such an ability requires self-awareness. If deception occurs at all, it is likely to be rare: like the boy who cried “Wolf!” you can’t do it very often if your credibility is to be preserved.

Byrne and Whiten became interested in deception after seeing several instances of what could be interpreted as such among a troop of baboons they were observing in the Drakensberg Mountains of southern Africa. For instance, one day Paul, a juvenile male, approached Mel, a mature female, who was engaged in unearthing a succulent tuber. Paul looked around, and saw that no other baboons were in sight, although he was surely aware that they were not far away. Paul let out a piercing scream, as if he were in danger. Paul’s mother, who was dominant to Mel, reacted as any protective mother would: she rushed to the scene and drove Mel, the apparent offender, away. Paul then casually ate the abandoned tuber. Had Paul thought, “Hmm, if I scream, my mother will assume Mel is attacking me. She’ll run to defend me, and I will be left with the juicy tuber to eat"? If true, this would be an example of tactical deception.

Byrne and Whiten thought it might be true, and informally canvassed fellow primatologists about their field observations. Many stories similar to Paul’s were told, although few had ever made it into the pages of the scientific literature, being anecdotal and therefore unscientific. Byrne and Whiten conducted surveys of more than a hundred of their colleagues, in 1985 and again in 1989, soliciting accounts of putative tactical deception. They received more than three hundred. The instances were not confined to observations of apes but included observations of monkeys as well. Interestingly, no one claimed to have seen deception in primates other than monkeys and apes, such as bush babies and lemurs.

The problem primatologists face in looking for evidence of deception is this: Is the action truly an example of an individual reasoning, based on a sense of self? Or is it merely the outcome of learning, which does not require a sense of self? Paul, for instance, might simply have learned that under the circumstances he encountered, his screaming would gain him access to Mel’s tuber, in which case his action would be a learned response and not an act of tactical deception.

When Byrne and Whiten applied strict criteria to the supposed examples of deception, ruling out as carefully as they could possibilities of learning, they found that of the 253 cases assembled in the 1989 survey, only 16 could be said to reflect true tactical deception. All of these cases were apes, and most were chimpanzees. I’ll give one example, which was observed by the Dutch primatologist Frans Plooij while at Gombe Stream Reserve, in Tanzania.

An adult male chimpanzee was alone in a feeding area when a box was opened electronically, revealing the presence of bananas. Just then, a second chimp arrived, whereupon the first one quickly closed the box and ambled off nonchalantly, looking as though nothing unusual was afoot. He waited until the intruder departed, and then quickly opened the box and took out the bananas. However, he had been tricked. The intruder had not left but had hidden, and was waiting to see what was going on. The would-be deceiver had been deceived. This is a persuasive example of tactical deception.

Observations such as these open a window onto the mind of chimpanzees. These animals evidently experience a significant degree of reflective consciousness, a conclusion that researchers who work with chimps on a day-today basis enthusiastically endorse. Chimpanzees exhibit a strong sense of awareness in the way they interact with each other and with humans. They are mind readers as humans are, but more limited in their scope.

In humans, mind reading goes beyond simply predicting what others will do under certain circumstances: it includes how others might feel. We all experience sympathy, or empathy, for others when they face situations we know to be painful or distressing. Vicariously, we experience the anguish of others, sometimes so intensely as to suffer physical pain. The most poignant vicarious experience in human society is the fear of death, or simply death awareness, which has played a large part in the construction of mythology and religion. Despite their self -awareness, chimpanzees at best seem puzzled about death. There are many anecdotal accounts of individuals, or even families, being distressed or disoriented when a relative dies. For example, when a small infant dies, its mother sometimes carries the tiny corpse around for a few days before discarding it. The mother seems to be experiencing bewilderment rather than what we call grief. But, how would we
know?
More significant, perhaps, is the lack of what we would recognize as sympathy for the bereaved mother from other individuals. Whatever the mother suffers, she suffers alone. The chimpanzees’ limitation in empathizing with others extends to themselves as individuals: no one has seen evidence that chimps are aware of their own mortality, of impending death. But, again, how would we
know?

What can we say about how self -aware our ancestors were? Some 7 million years have passed since humans and chimpanzees shared a common ancestor. We must therefore be cautious about assuming that chimps have remained unchanged, and that by looking at chimps we are effectively looking at that common ancestor. Chimps must have evolved in various ways since diverging from the humanlineage. But it is plausible to suggest that the common ancestor, a large-brained ape that lived a socially complex life, would have developed a chimpanzee level of consciousness.

Let’s assume that the common ancestor of humans and African apes possessed a level of self-awareness equivalent to that experienced by modern chimpanzees. From what we’ve learned about the biology and social organization of the australopithecine species, they were essentially bipedal apes: the social structure among these species would have been no more intense than we see among modern baboons. There is therefore no cogent reason why their level of self-awareness would have been enhanced during the first 5 million years of the human family’s existence.