More than Nature Needs

Derek Bickerton

• Publisher: Harvard University Press
• Year: 2014
• ISBN:
  9780674728530
• Topic: Biological Sciences
• Subtopic: Evolution
• Index: Biological Sciences

The human mind is an unlikely evolutionary adaptation. How did humans acquire cognitive capacities far more powerful than anything a hunting-and-gathering primate needed to survive? Alfred Russel Wallace, co-founder with Darwin of evolutionary theory, saw humans as "divine exceptions" to natural selection. Darwin thought use of language might have shaped our sophisticated brains, but his hypothesis remained an intriguing guess--until now. Combining state-of-the-art research with forty years of writing and thinking about language evolution, Derek Bickerton convincingly resolves a crucial problem that both biology and the cognitive sciences have hitherto ignored or evaded.What evolved first was neither language nor intelligence--merely normal animal communication plus displacement. That was enough to break restrictions on both thought and communication that bound all other animals. The brain self-organized to store and automatically process its new input, words. But words, which are inextricably linked to the concepts they represent, had to be accessible to consciousness. The inevitable consequence was a cognitive engine able to voluntarily merge both thoughts and words into meaningful combinations. Only in a third phase could language emerge, as humans began to tinker with a medium that, when used for communication, was adequate for speakers but suboptimal for hearers.Starting from humankind's remotest past, More than Nature Needs transcends nativist thesis and empiricist antithesis by presenting a revolutionary synthesis--one that instead of merely repeating "nature and nurture" clichés shows specifically and in a principled manner how and why the synthesis came about.

CHAPTER 1

Wallace’s Problem

The structure of this book is simple. In this chapter I state a problem and outline what I think is its solution. The rest of the book consists of arguments and evidence that support this solution. The problem itself, though quite easy to state, has ramifications that will take us through the territories of a number of disciplines, including evolutionary biology, paleoanthropology, psychology, neurobiology, and linguistics. Rest assured that everything will eventually lead us back to this same question, one of the most crucial anyone can ask: How did the human species acquire a mind that seems far more powerful than anything humans could have needed to survive?

Since it is becoming a custom to name problems after people (Plato’s problem, Darwin’s problem, Orwell’s problem, etc.), let us call this problem Wallace’s problem, since it was Alfred Russel Wallace, cofounder with Darwin of the theory of evolution through natural selection, who was the first to state it clearly and unequivocally. In his own words, “Natural selection could only have endowed the savage with a brain a little superior to that of an ape whereas he possesses one very little inferior to that of an average member of our learned societies” (Wallace 1869: 204). By “savage,” the customary expression of the time, Wallace meant only someone who had had what many nowadays would consider the good fortune to be born into a preliterate, pre-industrial society. His estimate of “savage” intellectual capacity was actually pretty enlightened for that time—decades would pass before anyone had the honesty to replace “very little inferior” with “equal.” And yet recognizing the universality of human intelligence gave Wallace only disquiet.

If evolution was a gradual process, and natural selection responded only to the demands placed on animals by their environment, then humans should have had a brain “little superior to that of an ape.” A brain slightly better than an ape’s would have enabled them to outsmart anything else on two legs or four, to reach the top of the food chain. Early humans didn’t need to do math, build boats, compose music, or have ideas about the nature of the universe in order to do all the things early humans did. That they should suddenly find themselves endowed with brains that could potentially enable them to do all these things was remarkable enough. But more remarkable yet was the fact that those same brains would make it possible for their possessors to cover the entire world with their works, to plunge into the deepest depths of the ocean, to soar into the highest reaches of the atmosphere, and (less that half a century after Wallace’s death) to leave even the Earth itself behind.

Wallace couldn’t bring himself to believe that natural selection alone could have done all this. There must have been some form of supernatural influence involved in the sudden and abrupt creation of the immense gap between human mental abilities and those of any other species. This gap seemed especially remarkable because nothing similar existed anywhere else in nature. What appeared elsewhere was exactly what any theory of evolution through natural selection would have predicted: isolated islands of highly task-specific adaptation, backed by otherwise smooth gradations of cognitive capacity across the entire range of species, leaving only humans as remote and exotic outliers.

Many writers on the history of evolutionary theory have attributed Wallace’s views on human evolution to his conversion to spiritualism—a good way of making his problem disappear. But regardless of what Wallace believed, his problem remains. The human mind is a profoundly unlikely evolutionary development, from any perspective, and we should honor Wallace’s honesty in facing this problem, regardless of how we feel about the solution he proposed.

Though Wallace was the first to clearly articulate the problem, it is almost certainly something that earlier minds were in some sense aware of. When Shakespeare wrote the lines that form the first epigraph to this book, he was purportedly expressing no more than Lear’s anger at his daughter for limiting the number of his attendants. But with Shakespeare there is always layer upon layer of meaning beneath the lines (one reason he is the greatest of writers). Underlying these particular lines is his awareness that even the “basest” of humans had far more than was needed for purely material purposes and that the lives of “beasts” are, in comparison with ours, far more limited. How this could have come about without the intervention of any mysterious extra-evolutionary forces is the topic of this book.

Darwin’s Response

Darwin certainly realized what the problem was. He had “no doubt that the difference between the mind of the lowest man and that of the highest animal is immense” (Darwin 1871: 100). He repeated Wallace’s estimate of “savages,” pointing out that the three natives of Tierra del Fuego who had accompanied him on the Beagle “resembled us in disposition, and in most of our mental faculties.” However, at the same time he ingenuously disarmed the argument from the gap between ape and human by citing against it the continuous gradation of intellect across the “much wider interval in mental powers” between “the lower fishes” and “the higher apes.” If there was a gradation in the one case, then there must, contrary to appearances, be a gradation in the other, since “there is no fundamental difference of this kind” (34).

This is sheer sleight of hand. The gradation of intellect between lamprey and chimpanzee is an argument not against the gap but for it. If there are countless species with abilities partway between those of lamprey and chimp, there should also be many species intermediate between chimps and humans. How is it that there are no animals with small or moderate amounts of self-consciousness, gradually increasing degrees of innovation and creativity, varying levels of artistic achievement (perhaps in only one or two of the arts), or at least a rudimentary language? The flat assertion of “no fundamental difference” is not (and could not have been, even in Darwin’s time) a scientific statement. It was and is a pure declaration of faith.

Darwin sought to give empirical backing to this declaration by the same means he used to support his claims in The Origin of Species: by accumulating a large stock of mostly anecdotal reports of behavior in other animals. But what is valid where there is also objective evidence in the physical forms of the various species involved is much less so when mental capacities are at issue. Since there is no unambiguous objective evidence to support these anecdotes, subjective interpretations, notoriously variable and unreliable, have to be unquestioningly relied on. A widespread human tendency to anthropomorphize puts its stamp on far too much of the evidence here.

Yet even here Darwin, ever a cautious thinker, hedges his bet. He continues to profess his faith that “the difference in mind between man and the higher animals, great as it is, is certainly one of degree and not of kind.” But the examples he cites in the same paragraph all involve emotions rather than cognitive processes. He feels forced to immediately suggest a fall-back position: “If it be maintained that certain powers, such as abstraction, self-consciousness etc., are peculiar to man, it may well be that these are the incidental results of other highly-advanced intellectual faculties; and these again are mainly the result of the continued use of a highly-developed language” (1871: 103).

This was a brilliant insight, but in Darwin’s day it could not have been more than a promissory note. Darwin did not and in the second half of the nineteenth century could not have cashed it out even in terms of hypothetical proposals, let alone plausible mechanisms backed by empirical evidence. Besides, to him it was simply Plan B, something he confidently believed he would never need. Future research, he must have thought, would surely spell out in detail the missing pieces, the discoveries that would show animal powers to be really only a little less than human.

And that, for a century, was that. No one attempted to solve Wallace’s problem. No one would even admit that there was such a thing, which saved them from the difficult if not impossible task of explaining why it wasn’t a problem. Of course if you were a creationist or believed in any form of spiritual intervention, there was no problem. God, or the Life Force, just did it. Nothing illustrates the intellectual incapacity of creationists and believers in intelligent design better than their almost total failure to exploit this issue. Repeatedly in their literature these groups claim as one of their strongest arguments against evolution the “fact” that no form intermediate between apes and humans has been found. Only a mouse-click away from them are a score of sites where they would learn that, far from an absence, there is an embarrassing number of intermediate forms, providing endless fuel for paleontological argument—not about whether these are really intermediates but simply over issues like whether they are directly ancestral to humans or on a side branch, whether specimen X should be assigned to species A or B, or whether, for that matter, A and B shouldn’t be merged (except for those who maintain that B should be subdivided into species C and D). In other words, normal science in progress. But creationists and designers alike have focused almost exclusively on physical form, where there is abundant evidence for evolutionary continuity, rather than on cognitive behavior, where there is little or none.

Evolutionists should be properly grateful for this misdirection. The cognitive gap between humans and nonhumans is evolution’s Achilles’ heel. Wallace’s problem is real, and evolutionists have simply ignored it or tried to explain it away. The only author I know of who has restated it is David Premack (1986: 133), who noted that “human language is an embarrassment for evolutionary theory because it is vastly more powerful than one can account for in terms of selective forces.” Everyone else has simply repeated, in one form or another, the mantra that humans are just “another unique species” (Foley 1987). Researchers have assembled massive lists—this time based on much more than anecdotal evidence—of all the clever things that other animals can do (see, e.g., some of the commentaries on Penn et al. 2008).

In some quarters it has become politically incorrect even to mention all the clever things that humans can do and animals can’t. But there can be no question that such things exist. “Human animals—and no other—build fires and wheels, diagnose each other’s illnesses, communicate using symbols, navigate with maps, risk their lives for ideals, collaborate with each other, explain the world in terms of hypothetical causes, punish strangers for breaking rules, imagine impossible scenarios, and teach each other how to do all of the above” (Penn et al. 2008: 109). If it is true that “for over 35 years, researchers have been demonstrating through tests both in the field and in the laboratory that the capacities of nonhuman animals to solve complex problems form a continuum with those of humans” (Pepperberg 2005: 469), how can this be? One’s initial reaction may well be that both statements can’t be true. But they are. This is just one of the paradoxes that Wallace’s problem forces us, or should force us, to face.

In practice it doesn’t, because after Premack rudely resurrected the problem, silence followed. Even Noam Chomsky, who for many years had insisted that language at least was totally divorced from anything other animals did, finally entered the fold and accepted the conventional wisdom that other animals have, among them or between them, all the bits and pieces required for language except perhaps one (Hauser et al. 2002; Chomsky 2007). But surely it can’t be long before some creationist or believer in intelligent design catches on to the fact that Wallace’s problem is the ideal place for inserting the “wedge” that creationists are always talking about (Johnson 1997). If that happens, science will find itself in a very embarrassing position, because as of now a scientific solution to Wallace’s problem just doesn’t exist.

The Key to the Problem

The key to the problem lies in Darwin’s Plan B, cited above: “It may well be that [abstraction, self-consciousness, etc.] are the incidental results of other highly-advanced intellectual faculties; and these again are mainly the result of the continued use of a highly-developed language.”

This notion, if seriously advanced, is bound to meet with consumer resistance. For many people, language is merely “a means of communication.” Like the Morse code or semaphore flags, it is not in itself constitutive of meaning but merely transmits meanings that have come from somewhere else. First you must “have a thought,” which you then dress up in words, though exactly what a thought is and where it comes from is far less clear than what words are and where they come from. For such persons, Darwin had it backward. First human intelligence must have developed, and only after long development could anything like language have emerged.

“Intelligence” has proved extremely difficult to define, and we would have a hard task on our hands if we were asked to find another species whose particular abilities derived from any kind of superior “general intelligence” that set them apart from other species. In most cases it’s the other way around. In other species, it’s glaringly obvious that cognitive skills are geared to very specific behaviors: spider intelligence to web spinning, beaver intelligence to dam building, bat intelligence to echolocation, bee intelligence to pollen gathering, and so forth. In the case of apes, there might seem to be a less narrowly focused intelligence than in the species I’ve mentioned. It’s as if social intelligence, notoriously their strong suit, had spilled over into other areas—a natural enough development, since social intelligence has to be more flexible, able to cope with constantly changing roles and status levels, if it is to work at all. It is also true that apes, like dogs but even more so, can be trained by humans to do a few of the things that otherwise only humans do. But apes, left to themselves, have never innovated the kinds of thing they are taught, whereas humans, unless taught by space aliens, must have spontaneously produced innovations over and over again.

What all this means is that, in terms of evolution, any “increase in intelligence” that is not motivated by the specific demands of a particular species’ niche is highly unlikely, perhaps even an impossibility. What most often, perhaps always drives increase of intelligence is the development of some very specific ability that is required if the species is to solve an ecological problem, such as how to catch fast-moving and skillfully maneuvering flying insects during the hours of night. The way increases of intelligence arise forms only one aspect of an even more general evolutionary process, covering every aspect of form and behavior: “The diversity of species … represents variation in design suggestive of adaptation to specific tasks” (Weibel 1998: 1, emphasis added).

Normally, specialized intelligence doesn’t spread to inform other areas precisely because it has to be focused on a very narrow range of behaviors. (Gardner [1983], with his “multiple intelligences,” and evolutionary psychology’s “Swiss army knife” approach to intelligence [e.g., Barkow et al. 1992] deal with similar issues from somewhat different perspectives.) But in very rare cases an initially focused kind of intelligence may be able to spread.

What is still lacking is any understanding of how and why and under what set of circumstances a focused intelligence could spread, and especially how all this could have come about in the specific case of humans and only among humans. The kind of answer one gets is all too often along the lines of this: “One possibility … is that recursion in animals represents a modular system designed for a particular function (e.g. navigation) and impenetrable with respect to other systems. During evolution, [this system] may have become penetrable and domain-general.… This change from domain-specific to domain-general may have been guided by particular selective pressures, unique to our evolutionary past, or as a consequence (by-product) of other kinds of neural re-organization” (Hauser et al. 2002: 1578, emphasis added). Such pronouncements merely restate the problem in a more complicated way without shedding any light on it.

We will have to do a lot better than that. Having identified the key source of human intelligence, we will have to show how that particular source was able to create the thoroughly convincing illusion that human “higher powers” spring from possession of some overarching, all-purpose intelligence.

But if, following Darwin, that key source is identified as language, we face serious obstacles. Language is a clear candidate, of course, because it is a very specific and specialized form of behavior and because the mechanisms through which it operates are clearly identifiable and well-studied (especially as compared with things like abstraction, consciousness, foresight, or imagination). Thus it fits the normal evolutionary profile of how increases in intelligence come about. However, it seems to yield no clues as to how that intelligence could have generalized across the entire spectrum of behaviors. Thus either Darwin’s Plan B is wrong, or we do not yet have any adequate understanding of what language is and does. I would opt for the second of these choices.

This claim may seem both arrogant and misguided, given the existence of a whole slew of linguistic theories worked out by dedicated professionals. It would indeed be so but for one fact: theories of language, without exception, have been worked out on the basis of synchronic linguistic evidence, without paying any attention to lang...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright
• Dedication
• Contents
• Epigraphs
• 1. Wallace’s Problem
• 2. Generative Theory
• 3. The “Specialness” of Humans
• 4. From Animal Communication to Protolanguage
• 5. Universal Grammar
• 6. Variation and Change
• 7. Language “Acquisition”
• 8. Creolization
• 9. Homo Sapiens Loquens
• References
• Acknowledgments
• Index