Kanzi: The Ape at the Brink of the Human Mind (44 page)

One day Nick showed me a tape of some of the last surviving stone tool manufacturers, who live in a remote section of the New Guinea highlands. These men learned their skills as youths, before their people had experienced any contact with the outside world. It was clearly an activity they enjoyed and were quite proficient at. They talked and sang as they worked, sometimes hardly even watching their own handiwork, it was so second nature to them. The knowledge of how to construct the tools seemed to reside in their hands rather than in their head. Their heads were busy spinning tales of past and future occasions where tools had been and would be needed.

The 50 percent jump in brain size between
Australopithecus
and
Homo habilis
seems to reflect the increased need to plan ahead that makes stone tool production possible. As man began to plan further and further ahead, he surely constructed increasingly elaborate mental models of what might happen in the future. At some point, he inevitably began to construct multiple models, each with different plausible scenarios and each requiring a different sort of preparation. At that point, man could no longer coordinate his behavior effectively with glances, gestures, emotions, and common knowledge of the situation. To coordinate and select between different mental models of the future, man needed language. With language he could describe his model of the anticipated future to others. This holding in mind, and contrasting of multiple models, must have required an increase in cortical capacity. However, the actual making of the tools and even the syntactical and phonemic skills used to describe the various mental models are, and probably were, rather automatized and once acquired, needed little additional cranial space. Potential mental models of the future are not the kinds of ideas that readily become automatized. They tend to remain in conscious awareness and to be constantly updated by the events at hand.

Somewhere between five hundred thousand and fifty thousand years ago, a hominid species became human, as
Homo erectus
gave way to
Homo sapiens
. At first these
Homo sapiens were
archaic in form, but by one hundred thousand years ago, they began to merge into the form we know today. During the same time, technology progressed from the simplest manufacture and use of stone flakes and cores to the production of elaborate implements that required a clear mental concept, or template, and considerable manual dexterity. Ultimately, some tools took on an aesthetic appearance, too, in the form of beautifully fashioned and decorated implements made of stone, bone, and antler. About thirty thousand years ago, during the period archeologists call the Upper Paleolithic, artistic expression became manifested, in the form of body ornamentation, images painted and engraved on walls, and the carving of bone and ivory figures. Compared with archeological evidence of human behavior earlier than thirty thousand years ago, the advent of the Upper Paleolithic was a dramatic and explosive event, and it included the practice of elaborate rituals, the establishment of larger communities, and the development of long-range contacts, possibly involving trade. Methods of hunting became much more efficient, and people began to settle in the far reaches of the world, including Australia and the Americas. Revolution is not too strong a word to describe the magnitude and rate of change that took place.

There is no doubt that the nature of human behavior we see in the Upper Paleolithic was an expression of the modern human mind. However, there is currently little agreement as to degree to whether these behavioral changes were biologically or culturally driven. The puzzle archeologists face is this: If anatomically modern humans evolved a hundred thousand years ago, why did modern human behavior not appear until some seventy thousand years later? The fact that no obvious anatomical change corresponded to what can only be called the dawn of cultural life has led many to ponder the place of language in this set of events.

Was it language that made all of this possible? Iain Davidson certainly thought so, and he was the first to have had the patience to explain the cultural explosion in such detail to me that I began to grasp the full weight of its importance.

To Iain,
Homo erectus
had barely even taken the first step on the journey toward modern human behavior, let alone progressed some distance on it. “We propose that all human ancestors without language should be considered as closer to chimpanzees than to modern humans in their behavior,” Iain wrote in a paper he co-authored with William Noble for the Cascais conference volume. “Two events in the record of prehistoric evolution of human behavior can be said to be the first that unambiguously entail the existence of language: the colonization of Australia, before 40,000 years ago, by people crossing the sea to an unknown shore; and the appearance of sculptures and bas reliefs with coded symbols in different parts of Europe before 32,000 years ago.”
¹¹

Iain and his colleague have developed a hypothesis that argues that before our ancestors created images, not only
did they not
have language, but they
could not
have had language. They acknowledge that the art of Upper Paleolithic Europe betrays the existence of full-blown symbolic language, and suggest that earlier, more primitive image-making activities must have preceded it. These earlier stages would have marked the emergence of the referential abilities that characterize image making and symbolic language. True language evolved sixty thousand years ago, or perhaps a little earlier, suggests Iain. Prior to that, our ancestors’ vocal skills were mere “context specific communications.”
¹²

Iain and Bill’s argument is twofold. First, it dismisses the suggestion that the Acheulian handaxe implies intentionality on the part of the tool-maker and therefore the inferences of cognitive and linguistic skills that go with it. They claim, instead, that the characteristic shape of the handaxe is the incidental outcome of removing many flakes from a particularly large core, not the deliberate fashioning of a shape according to a mental template. And the consistency of shape through space and time is the result of “a small number of learned motor actions,”
¹³
not the systematic imposition of arbitrary form. They point out that the sticks made by chimpanzees to catch termites conform to local regularity, and that this conformity should be interpreted as a consequence of the chimps having a small repertoire of actions for preparing the tool.

“If handaxes were produced according to a mental template, that would indeed imply considerable intentionality,” Iain observes. “The hominid would be sitting there for fully ten or fifteen minutes, working steadily toward a planned goal, and that is not a trivial intellectual exercise. But the paradox of the archeological record is that there is absolutely no other evidence of this putative level of intentionality. If that competence were present, you would see evidence of it,” concludes Iain.
¹⁴

Although Nick Toth concedes that Iain has a good point, he rejects the notion that Acheulian handaxes are the byproducts of repetitive flaking. “It makes no sense to me,” he says. “If you do what he says, you finish up with a discoidal core, not a tear-drop shaped handaxe.”
¹⁵

When Iain was visiting the Language Research Center early in 1993, I thought I would perform a small test of his hypothesis, and so challenged him to produce a handaxe by knocking flakes off a large core. He had to be guided only by the need to remove flakes efficiently, I charged, and must not intentionally produce the characteristic shape of the Acheulian axe. He failed. Perhaps the test was unfair, because flaking is a considerable skill in itself, and Iain was not fully adept at it. My view is that Iain is probably wrong on this point, and that
Homo erectus
stone knappers knew what they were aiming for when they made handaxes.

The second line of argument in Iain and Bill’s hypothesis relates to the nature of language itself. The essence of symbolic language is its referential nature, the act of invoking through the use of symbols an event or object in its absence. Words come to replace, or refer to, those actions or objects in the minds of speaker and listener. The ability to displace reference to an object from the presence of the object itself was engendered by the act of using images, Iain and Bill argue. The scenario is something like the following.

An individual points to a bison and perhaps vocalizes but, critically, makes a simple iconic image in the soil or on a wall, perhaps reflecting the curve of the head and back. Later, that same image invokes the notion of bison, but in the absence of the animal; and so might the associated vocalization. The crucial
mediator in the process, insist Iain and Bill, is the production of the visual image that separates the object from a reference to it. “Depiction . . . provokes the reflectivity that in turn permits referential utterance,” they wrote in a scientific paper.
¹⁶
“Communication is common to many creatures, but only humans have the capacity to communicate their meanings independent of context.”
¹⁷

If Iain is correct and language as we know it appeared on the scene only forty thousand years ago, this means that large-brained
Homo sapiens
existed on this planet for nearly sixty thousand years without language. It means that in the forty thousand years since we invented language we have come to depend on it so completely that we now believe it to be innate. It also means that
Homo erectus, Homo habilis
, and
Australopithecus
could not have had anything like language. I finally began to see why it was that Iain was wary of the data I had assembled on Kanzi. I also began to wonder what it could have been like to be a member of a human group in which people communicated by nonverbal expressions and gestures, but did not use language. If Iain is correct, what were we like before we invented language? I thought of those vague references to “dreamtime” people in aboriginal cultures, and the references in our own culture to the absence of “knowledge of good and evil” before Eve consumed the proverbial apple. I also recalled those references to some African and Indian cultures in which it is said that older brother and younger brother decided upon different paths long ago when they first became aware that it was possible to control fire. It is said that the older brother elected to remain in the forest, following the old ways and eschewing fire and language. The apes of today are descended from older brother. Younger brother went out from the forest and kept fire with him, becoming the progenitor of all humans today. Could cultural myths such as these hark back to a murky time in our distant past when we possessed human minds but no language?

Though I greatly admired Iain’s work, it was difficult to accept his view that language was a recent visitor on the evolutionary playing field. If this were true, how could Kanzi understand
complex, novel sentences like, “Can you go scare Matata with the snake?” I knew my data were sound. Iain had a similar confidence in his data. Moreover, we each respected the care and critical eye that the other brought to the process of reconstructing the roots that undergird human existence. Could such diverse perspectives meet?

Language arose in a particular manner in human prehistory, and this process must have impressed itself in a consistent way in the evidence available today. Read correctly, these lines of evidence, together with those from modern neurology and psychology, should therefore tell the same evolutionary story. Yet two extreme views of language origins have emerged from this data. The differences that Iain and I shared were symptomatic of the disparate opinions regarding the role of language in human evolution.

The existence of such divergent views on the origin of language suggests that, in some way, the archeological and fossil evidence is being misread. Although my initial motivation for working with apes was to help in the search for a greater understanding of human behavior, I have been unquestionably affected by the data unfolding over the past decades. These recent studies have become increasingly relevant to the unresolved question of the evolution of human language. The data provided by the abilities of Sherman and Austin, coupled with the data of Kanzi and Panbanisha, provide an independent means to evaluate the two models of language origins.

While what we have learned about the linguistic and tool-constructing capacities of apes does not tell us
how
hominids became human, it does tell us a great deal about the common substrate of mind shared by apes and our hominid ancestors. Our modern minds evolved from these ancestral minds, which must have shared many characteristics with apes not too different from those alive today. Thus Kanzi and other apes offer a glimpse of the starting point in man’s evolutionary transformation from a state of nature to the modern human condition.

In his second most famous book,
The Descent of Man
, Charles
Darwin noted the great paradox of the gap between human achievement and that of the rest of the animal world. “[T]here is no fundamental difference between man and the higher mammals in their mental faculties,” he observed. And yet, he acknowledged, “Of the high importance of the intellectual faculties there can be no doubt, for man mainly owes to them his predominant position in the world.”
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