Kanzi: The Ape at the Brink of the Human Mind (6 page)

In a book written in 1863 entitled
Evidence as to Man’s Place in Nature
, Thomas Henry Huxley recognized the close anatomical relationship between the African apes and man. The orangutan, an Asian ape, was said to be more distantly related. Huxley concluded that the African apes and man should be placed in the same taxonomic family. Although Huxley’s recommendations were ignored at the time, a century later, Morris Goodman of Wayne State University confirmed them at the molecular level. Goodman, like Huxley before him, proposed a reclassification of man and ape at a Wenner-Gren conference in 1962. Goodman, again like Huxley before him, was roundly rebuked for suggesting that the biological data indicate that man and the African ape should be placed in the same family, which would make them as closely related as, for example, the spinner dolphin and the bottle-nosed dolphin.

In the three decades since Goodman’s pioneering work, a vast flood of molecular biological evidence has confirmed his—and Huxley’s—conclusions. Pressure is consequently mounting
to reclassify humans and great apes in a way that reflects evolutionary and biological reality. Humans and the African apes differ in about 1 percent of their DNA. This means that apes are far more closely related to us than they are to monkeys. Yet many people still have difficulty even telling the difference between an ape and a monkey. Monkeys have tails, apes do not. Apes are built very much like us; monkeys have a wide variety of anatomical types, but in general their shoulders, hips, and torso all articulate in a manner similar to other quadrupedal mammals and very different from apes. Apes, like ourselves, are built on the “upright plan,” which means that we, and they, tend to orient toward each other in an upright position much of the time. The upright position may be achieved by being suspended from a branch, by sitting, or by standing.

There are differences between ourselves and apes, of course. The most striking is that the size of our brain is three times that of an ape. And then there are the behavioral differences. None championed these more strongly than Huxley himself, even though he argued that man and ape belonged in the same taxonomic family. “No one is more strongly convinced than I am of the vastness of the gulf between . . . man and the brutes . . . for he alone possesses the marvelous endowment of intelligible and rational speech [and] . . . stands raised upon it as on a mountain top, far above the level of his humble fellows, and transfigured from his grosser nature by reflecting here and there, a ray from the infinite source of truth.”
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Huxley’s views are widely echoed today. Simply put, they state that language makes it possible for we humans to transcend our biology and thus enter a state of being so different from that experienced by any animals as to render a complete discontinuity between their life experiences and our own.

How did humans come to possess so remarkable a means of communication? Is language a highly developed extension of the communication systems already in use by other primates, or does it represent a complete break, a way of communicating that is so different from that of other species that it makes a completely new form of thought—rational thought—possible? The rationale of ape-language
research, of course, is that the cognitive foundations of modern human speech are likely to be found in the great apes, our closest evolutionary relatives, and perhaps in other higher mammals as well. Much of modern linguistics is dominated by the opposite view.

Since the late 1950s, Noam Chomsky, of the Massachusetts Institute of Technology, has argued forcefully for the complete and singular independence of language from all other forms of communication and thought. According to this view, it is the syntactical structure underlying language that, in effect, makes language possible. Without this structure, Chomsky argues, we would be limited simply to expressing linear unrelated concepts and to reacting to single events, one at a time. According to Chomsky, this underlying structure, once it is fully understood, will be found to be identical across all languages and all cultures; that is, it will manifest the universal properties of human intelligence. The ability to relate world events in a causal-linear manner is thought to derive from this structure, and consequently to be as innate a portion of our biology as are our eyes, our hands, or our internal organs. According to Chomsky, “the child approaches the task of acquiring a language with a rich conceptual framework already in place and also a rich system of assumptions about sound structure and the structure of more complex utterances.” In Chomsky’s view these assumptions “constitute one part of the human biological endowment, to be awakened by experience and to be sharpened and enriched in the course of the child’s interactions with the human and material world.”
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Chomsky argues that one should study language “exactly the same way you’d study an organ, say, the heart.”
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To Chomsky, this means that we need to open up the “language module” and understand its structure, just as we have done with the heart. Just as we have learned that blood flows from the heart to the lungs and back again to be pumped to the rest of the body, we need to understand how syntactical rules regulate the flow of our speech.

When the 1990 Wenner-Gren conference began, therefore, it was with the boundary between humans and nonhumans still
being policed and maintained by the scientific community at large, with Chomsky as their guardian.

Kathleen Gibson set the stage for the conference, briefly sketching the intellectual questions we were to address. She reminded us that while paleoanthropology had progressed in understanding the evolution of the physical form of
Homo sapiens
, the origin of the mind was still swathed in mystery. Perhaps this should not be surprising, as neuroscientists also have found it difficult to answer a basic question about how the brain functions: Are cognitive skills such as reasoning, language, music, and art controlled by discrete modules within the brain, or by the interrelated agents of a distributed system? Evidence has been adduced for both positions, but nothing is conclusively settled.

Until the structure-function relationship of the modern human brain can be described accurately, any understanding of the dynamics of the evolution of the mind must rely on indirect evidence, such as behavior (that of modern humans compared with African apes, and that preserved in the archeological record). Psychobiologists, such as myself, don’t often sit at the same conference table as archeologists, but that lofty aim was why we were in Cascais. We each had a view of the value of our own contribution, as I was soon to learn. To me, it seemed obvious that studies of chimpanzees, humans’ closest evolutionary relative, offered us our best insights into the emergence of human mind.

I was therefore incredulous when, on the very first morning of the conference, Iain Davidson, an archeologist from the University of New England, Australia, began to speak, saying, in essence, “Humans are different from apes, and all the ‘chimpology’ in the world won’t tell us anything of interest; chimps [aren’t] representational thinkers, therefore we [can’t] learn anything useful about language by looking at apes; training chimps to do tricks might be interesting in itself, but it is irrelevant to events in the past; and if you want to learn anything about language origins, the only place to look is at the
archeological record; psychologists behave as if prehistoric evidence doesn’t matter; finally, the archeological evidence suggests that human language arose very recently, within the last 100,000 years—so much for chimpology.”

Iain should have been aware that a word such as “chimpology” would grate on those of us at the conference who had devoted our lives to the study of apes. His assertion that nothing of interest could be learned from chimps about the nature of human language made me feel that an immediate response to such a totally homocentric position was sorely needed. I therefore vigorously objected to the idea that Kanzi had been
trained
to do anything, observing that Iain obviously hadn’t had much opportunity to learn what chimps were like. I noted that they easily handled symbolic representation, but I had to stop short of explaining the data that permitted these conclusions. My response had to be brief as Gibson and Ingold were careful to let others have an opportunity to respond, too.

I sat back thinking, “Oh no, another Chomskian! Another scientist whose mind is closed to what chimps can tell us about the human mind.” As others spoke I was amazed at the anthropocentric views of many around me. The reaction to language in apes was even more negative than I had feared. For some, Kanzi and other speaking apes were seen as little more than the ghoulish constructions of publicity-hungry scientists who sought to distort the natural order of things by creating apes who could talk. The idea that an ape might desire to learn to talk, for the purpose of communicating his or her thoughts to another species, was not one that many seemed interested in or able to grasp. The idea that we humans might learn something about the origins of our language and minds by observing how apes can go about developing these capacities seemed too remote to hope to present.

I soon learned, however, that Iain was as concerned about people failing to understand his perspective on archeology as I was about having my chimp work misunderstood. Consequently he had sought the very first opportunity to drive home the point that an event as salient as the origin of language, which took place in prehistory, is likely to have left its
mark on prehistory, and that this line of evidence had not received sufficient attention from people interested in language origins—particularly psychologists. I learned this only because that evening after supper I decided to muster my courage and go up and speak to Iain directly.

I started out by asking him how he could be so peremptorily derogatory about apes when he knew next to nothing about them. How was it he could so blithely assume that symbol capacities did not exist in creatures before they began to leave permanent statues, paintings, or other artifacts in the archeological record? Much to my surprise, Iain was not nearly as bombastic when approached one on one. I realized that he probably had been so stiff and argumentative because he was in front of the group. It seemed to me that human males often responded that way during initial encounters—just as do chimpanzee males. Unlike every other Chomskian I had met, Iain readily allowed that there was a great deal he did not know about apes, though he held fast to his notion that only man could symbolize.

Although our original intellectual positions seemed very far apart—with Iain proposing a late, sudden origin of language while I favored an early, more gradual efflorescence—we began that day one of the most productive, free-flowing exchanges of ideas I’ve been privileged to enjoy with a colleague. We both listened, and as a result began to modify our ideas. Iain wasn’t afraid to argue forcefully for his views, and neither was I, but somehow this did not keep us from talking to one another, as is so often the case with scientists who disagree. Why not? I think because we each accepted the other’s directness, even bluntness, without offense. We did so out of a mutual recognition of the integrity of the other person’s efforts. It was a remarkable week, one that may become a milestone in our important intellectual journey toward understanding the human mind—with the human/nonhuman boundary suffering badly.

Fortunately, it was not up to me alone to convince the gathering’s skeptics of the range and inventiveness that characterize ape intelligence. I was aware, of course, of chimpanzees’
penchant for using tools, but it wasn’t until Bill McGrew itemized the different types of tools they use, and in the many different circumstances, that its import became fully clear to me, and to others, too. “Chimpanzees are the only nonhuman species in nature to use different tools to solve different problems,” said McGrew, a primatologist at the University of Stirling, Scotland. “They go beyond using the same tool to solve different problems (for example, a sponge of leaves to swab out a fruit-husk or a cranial cavity) or different tools to solve the same problem (for example, probes of bark
or
grass
or
vine to fish for termites). Thus, they have a
tool-kit”
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