The Origin of Humankind

by Richard Leakey

  The eland is the most frequently depicted animal in San paintings, and its potency comes in many forms. Lewis-Williams wondered whether the horse and the bison were similar sources of potency for the Upper Paleolithic people—images that were appealed to and touched when spiritual energy was required. As a way of approaching this question, he needed evidence that Upper Paleolithic art, too, was shamanistic. A clue lay with the geometric signs.

  According to the psychological literature that Lewis-Williams surveyed, there are three stages of hallucination, each one deeper and more complex. In the first stage, the subject sees geometric forms, such as grids, zigzags, dots, spirals, and curves. These images, six forms in all, are shimmering, incandescent, mercurial—and powerful. They are called entoptic (“within vision”) images, because they are produced by the basic neural architecture of the brain. “Because they derive from the human nervous system, all people who enter certain altered states of consciousness, no matter what their cultural background, are liable to perceive them,” Lewis-Williams pointed out in a 1986 article in Current Anthropology. In the second stage of trance, people begin to see these images as real objects. Curves may be construed as hills in a landscape, chevrons as weapons, and so on. The nature of what the individual sees depends on the individual’s cultural experience and concerns. San shamans frequently manipulate series of curves into images of honeycombs, since bees are a symbol of supernatural power that these people harness when entering a trance.

  The passage from the second to the third stage of the hallucination is often accompanied by a sensation of traversing a vortex or rotating tunnel, and full-blown images—some commonplace, some extraordinary—may be seen. One type of important image during this stage is of human/animal chimera, or therianthropes, as they are called (see figure 6.1). These creatures are common in shamanistic San art. They are also an intriguing component of Upper Paleolithic art.

  The entoptic images of stage-one hallucination are present in San art, which may be taken as objective evidence that the art is shamanistic. And these same images are to be seen in Upper Paleolithic art, sometimes superimposed on animals, sometimes in isolation. In combination with the presence of enigmatic therianthropes, they are strong evidence that at least some of Upper Paleolithic art is indeed shamanistic. These therianthropes were once dismissed as the product of “a primitive mentality [that] failed to establish definitive boundaries between humans and animals,” as John Halverson put it. If, instead, they are images experienced in a trance, they were as real to the Upper Paleolithic painter as horses and bison.

  FIGURE 6.1

  A face from the past. Combinations of human and animal features, such as in the so-called Sorcerer from the cave of Trois Freres, in southwestern France, are not uncommon in Upper Paleolithic art. They suggest that the art is shamanistic in origin.

  When we think of art, we tend to think of a painting being made on a surface, whether it is a canvas or a wall. Shamanistic art is not like that. Shamans often perceive their hallucinations as emerging from rock surfaces: “They see the images as having been put there by the spirits, and in painting them, the shamans say they are simply touching and marking what already exists,” Lewis-Williams explains. “The first depictions were therefore not representational images in the way you or I think of them, but were fixed mental images of another world.” The rock surface itself, he notes, is an interface between the real world and the spirit world—a passageway between the two. It is more than a medium for the images; it is an essential part of the images and the ritual that went on there. Lewis-Williams’ hypothesis has attracted a good deal of attention and, inevitably, some skepticism. Its value is in allowing us to see the art through different eyes. Shamanistic art is so very different from Western art in its execution and its construal that through it we can look at Upper Paleolithic art in new ways.

  The French archeologist Michel Lorblanchet is also making us look at Upper Paleolithic art in different ways. For several years he has been doing experimental archeology, replicating images from the caves in an attempt to get a sense of the Ice Age artists’ tasks and experience. His most ambitious project was to re-create the horses of Peche Merle, a cave in the Lot region of France. The two horses face away from each other, rumps slightly overlapping, and stand about four feet tall. They have black and red dots on them and stencils of hands around them. Because the rock surface on which the images were painted is rough, the artists apparently delivered the paint by blowing it through a tube rather than using a brush.

  Lorblanchet found a similar rock surface in a nearby cave and determined to paint the horses anew, using a blowing technique. “I spent seven hours a day for a week, puff. . . puff. . . puff,” he told a writer for Discover. “It was exhausting, particularly because there was carbon monoxide in the cave. But you experience something special, painting like that. You feel you are breathing the image onto the rock—projecting your spirit from the deepest part of your body onto the rock surface.” This doesn’t sound like a very scientific approach, but perhaps so elusive an intellectual target requires unorthodox methods. Lorblanchet has been innovative in the past, with his previous ventures into replication. This one surely deserves consideration, too. If the paintings of the Ice Age were part of Upper Paleolithic mythology, then the painters did put their spirit onto the wall, no matter what method they used to apply the paint.

  We may never know what the Tuc d’Audoubert sculptors had in mind when they fashioned the bison, nor the painters at Lascaux when they drew the Unicorn, nor any of the Ice Age artists in what they did. But we can be sure that what they did was important in a very deep sense to the artists and to the people who saw the images in the generations afterward. The language of art is powerful to those who understand it, and puzzling to those who do not. What we do know is that here was the modern human mind at work, spinning symbolism and abstraction in a way that only Homo sapiens is capable of doing. Although we cannot yet be sure of the process by which modern humans evolved, we do know that it involved the emergence of the kind of mental world each of us experiences today.

  CHAPTER 7

  THE ART OF LANGUAGE

  There is no question that the evolution of spoken language as we know it was a defining point in human prehistory. Perhaps it was the defining point. Equipped with language, humans were able to create new kinds of worlds in nature: the world of introspective consciousness and the world we manufacture and share with others, which we call “culture.” Language became our medium and culture our niche. In his 1990 book Language and Species, the University of Hawaii linguist Derrick Bickerton puts this cogently: “Only language could have broken through the prison of immediate experience in which every other creature is locked, releasing us into infinite freedoms of space and time.”

  Anthropologists can be certain of only two issues relating to language, one direct, the other indirect. First, spoken language clearly differentiates Homo sapiens from all other creatures. None but humankind produces a complex spoken language, a medium for communication and a medium for introspective reflection. Second, the brain of Homo sapiens is three times the size of the brain of our nearest evolutionary relatives, the African great apes. There is certain to be a relationship between these two observations, but its nature is fiercely debated.

  Ironically, although philosophers have long pondered the world of language, most of what is known about language has emerged in the past three decades. Roughly speaking, two views have emerged concerning the evolutionary source of language. The first views it as a unique trait of humans, an ability that arose as a side consequence of our enlarged brain. In this case, language is seen to have arisen rapidly and recently, as a cognitive threshold was passed. The second position argues that spoken language evolved through natural selection acting on various cognitive capacities—including but not limited to communication—in nonhuman ancestors. In this so-called continuity model, language evolved gradually in human prehistory, beginning with the evolution of the ge
nus Homo.

  The MIT linguist Noam Chomsky has been principally associated with the first model, and his influence has been immense. To Chomskians, who represent the majority of linguists, there is little utility in looking for evidence of language capacity early in the human record, and still less in seeking it in our simian cousins. As a result, tremendous antagonism has been expressed toward those who try to teach apes some form of symbolic communication, usually via a computer device and arbitrary lexigrams. One of the themes of this book is the philosophical divide between those who see humans as special and separate from the rest of nature and those who accept a close link. Nowhere does this emerge more passionately than in the debate on the nature and origin of language. The vitriol hurled by linguists at apelanguage researchers undoubtedly reflects this divide.

  Commenting on those who argue for the uniqueness of human language, the University of Texas psychologist Kathleen Gibson recently wrote: “Although scientific in its postulates and discussion [this perspective] fits firmly within a long Western philosophical tradition, dating at least to the authors of Genesis and to the writings of Plato and Aristotle, which holds that human mentality and behavior [are] qualitatively different from that of animals.”

  As a result of this thinking, anthropological literature has long been littered with behaviors that were considered unique to humans. These include toolmaking, the ability to use symbols, mirror recognition, and, of course, language. Since the 1960s, this wall of uniqueness has steadily crumbled, with the discovery that apes can make and use tools, use symbols, and recognize themselves as individuals in a mirror. Only spoken language remains intact, so that linguists are effectively the last defenders of human uniqueness. They appear to take their job seriously.

  Language arose in human prehistory—by some means and along some temporal trajectory—and in so doing transformed us as individuals and as a species. “Language is, of all our mental capacities, the deepest below the threshold of our awareness, the least accessible to the rationalizing mind,” observes Bickerton. “We can hardly recall a time when we were without it, still less how we came by it. When we could first frame a thought, it was there.” As individuals, we depend on language for our being in the world and simply cannot imagine a world without it. As a species, it transforms the way we interact with each other, through the elaboration of culture. Language and culture both unite and divide us. The world’s five thousand extant languages are products of our shared ability, but the five thousand cultures they create are separate from one another. We are so very much a product of the culture that shaped us that we often fail to recognize it as an artifact of our own making, until we are faced with a very different culture.

  Language does indeed create a gulf between Homo sapiens and the rest of the natural world. The human ability to generate discrete sounds, or phonemes, is only modestly enhanced compared with this ability in apes: we have fifty phonemes; the ape has about a dozen. Nevertheless, our use of those sounds is virtually endless. They can be arranged and rearranged to endow the average human being with a vocabulary of a hundred thousand words, and those words can be combined in an infinity of sentences. As a consequence, the capacity of Homo sapiens for rapid, detailed communication and richness of thought is unmatched in the world of nature.

  Our task is to explain how language arose in the first place. In the Chomskian view, we need not look to natural selection for its source, because it is an accident of history, a capacity that emerged once some cognitive threshold was passed. Chomsky argues as follows: “We have no idea, at present, how physical laws apply when 1010 neurons are placed in an object the size of a basketball, under the special conditions that arose during human evolution.” Like Steven Pinker, a linguist at MIT, I reject this view. Succinctly, he asserts that Chomsky “has it backwards.” The brain is more likely to have increased in size as a result of the evolution of language, not the other way around. He argues that “it is the precise wiring of the brain’s microcircuitry that makes language happen, not gross size, shape, or neuron packing.” In a 1994 book, The Language Instinct, Pinker amasses the evidence in favor of a genetic basis for spoken language, which supports its evolution by natural selection. Too voluminous to go into now, the evidence is impressive.

  The question is, What were the pressures of natural selection that favored the evolution of spoken language? Presumably, the ability did not spring into being full-blown, so we have to wonder what advantages a less-developed language conferred on our ancestors. The most obvious answer is that it offered an efficient way to communicate. This ability, surely, would have been beneficial to our ancestors when they first adopted rudimentary hunting and gathering, which is a more challenging mode of subsistence than that of apes. As their way of life grew more complex, the need for social and economic coordination grew, too. Effective communication would have become more and more valuable under these circumstances. Natural selection would therefore have steadily enhanced language capacity. As a result, the basic repertoire of ancient simian sounds—presumably similar to the pants, hoots, and grunts of modern apes—would have expanded and its expression would have become more structured. Language as we know it today emerged as the product of the exigencies of hunting and gathering. Or so it might seem. There are other hypotheses for language evolution.

  As the hunting-and-gathering way of life developed, humans became technologically more accomplished, fashioning tools more finely and in more sophisticated forms. This evolutionary transformation, which began with the first species of the genus Homo, prior to 2 million years ago, and culminated with the appearance of modern humans, sometime within the last 200,000 years, was accompanied by a tripling of the size of the brain. It expanded from some 400 cubic centimeters in the earliest australopithecines to an average of 1350 cubic centimeters today. For a long time, anthropologists drew a causal link between increasing technological sophistication and increasing brain size: the former drove the latter. This, remember, was part of the Darwinian evolutionary package I described in chapter 1. More recently, this view of human prehistory was encapsulated in a classic 1949 essay by Kenneth Oakley titled “Man the Toolmaker.” As noted in an earlier chapter, Oakley was among the first to propose that the emergence of modern humans was triggered by the “perfection” of language to the level we experience today: in other words, modern language made modern man.

  These days, however, a different evolutionary explanation has become popular as an explanation of the making of the human mind—an explanation oriented more toward man the social animal than man the toolmaker. If language evolved as an instrument of social interaction, then its enhancement of communication in a hunting-and-gathering context can be seen as a secondary benefit and not the primary evolutionary cause.

  The Columbia University neurologist Ralph Holloway was an important pioneer of this new point of view, which was seeded in the 1960s. “It is my bias that language grew out of a social behavioral cognitive matrix which was basically cooperative rather than aggressive, and relied on a complemental social structural division of behavioral labors between the sexes,” he wrote a decade ago. “This was a necessary adaptive evolutionary strategy to permit an extended period of infant dependency, extended times to reproductive maturity, a delayed maturation permitting greater brain growth and behavioral learning.” Notice how this accords with the discoveries in hominid life history patterns, which I described in chapter 3.

  Holloway’s pioneering ideas have passed through several guises and have come to be known as the social intelligence hypothesis. Most recently, Robin Dunbar, a primatologist at University College, London, developed it as follows: “The more conventional [theory] is that [primates] need big brains to help them find their way about the world and solve problems in their daily search for food. The alternative type of theory is that the complex social world in which primates find themselves has provided the impetus for the evolution of large brains.” A vital part of modulating social interactions in primate groups is g
rooming, which allows close contact and monitoring between individuals. It is effective in groups up to a certain size, states Dunbar, but when that size is exceeded, other means of social lubrication are required.

  During human prehistory, group size increased, argues Dunbar, producing selection pressure for more efficient social grooming. “Language has two interesting properties compared to grooming,” he explains. “You can talk to several people at once and you can talk while travelling, eating or working in the fields.” As a result, he suggests, “language evolved to integrate a larger number of individuals into their social groups.” In this scenario, then, language is “vocal grooming,” and Dunbar sees it emerging only “with the appearance of Homo sapiens.” I have a lot of sympathy with social intelligence hypotheses, but, as I shall show, I do not believe language evolved late in human prehistory.

  The time at which language evolved is one of the basic issues in this debate. Was it early, followed by a gradual enhancement? Or did it originate recently and suddenly? Remember, the question has philosophical implications, relating to how special we view ourselves.