The Language Instinct: How the Mind Creates Language (56 page)

That is why the variation that geneticists tell us about is microscopic—differences in the exact sequence of molecules in proteins whose overall shape and function are basically the same, kept within narrow limits of variation by natural selection. That variation is there for a purpose: by shuffling the genes each generation, lineages of organisms can stay one step ahead of the microscopic, rapidly evolving disease parasites that fine-tune themselves to infiltrate the chemical environments of their hosts. But above the germ’s-eye view, at the macroscopic level of functioning biological machinery visible to an anatomist or psychologist, variation from one individual to another must be quantitative and minor; thanks to natural selection, all normal people must be qualitatively the same.

But this does not mean that individual differences are boring. Genetic variation can open our eyes to the degree of structure and complexity that the genes ordinarily give to the mind. If genes just equipped a mind with a few general information-processing devices like a short-term memory and a correlation detector, some people might be better than others at holding things in memory or learning contingencies, and that would be about it. But if the genes built a mind with many elaborate parts dedicated to particular tasks, the unique genetic hand that is dealt to each person would give rise to an unprecedented profile of innate cognitive quirks.

I quote from a recent article in
Science:

And both flushed the toilet both before and after using it, kept rubber bands around their wrists, and dipped buttered toast in their coffee.

Many people are skeptical of such anecdotes. Are the parallels just coincidences, the overlap that is inevitable when two biographies are scrutinized in enough detail? Clearly not. Bouchard and his behavior geneticist colleagues D. Lykken, M. McGue, and A. Tellegen are repeatedly astonished by the spooky similarities they discover in their identical twins reared apart but that never appear in their fraternal twins reared apart. Another pair of identical twins meeting for the first time discovered that they both used Vademecum toothpaste, Canoe shaving lotion, Vitalis hair tonic, and Lucky Strike cigarettes. After the meeting they sent each other identical birthday presents that crossed in the mail. One pair of women habitually wore seven rings. Another pair of men pointed out (correctly) that a wheel bearing in Bouchard’s car needed replacing. And quantitative research corroborates the hundreds of anecdotes. Not only are very general traits like IQ, extroversion, and neuroticism partly heritable, but so are specific ones like degree of religious feeling, vocational interests, and opinions about the death penalty, disarmament, and computer music.

Could there really be a gene for sneezing in elevators? Presumably not, but there does not have to be. Identical twins share all their genes, not just one of them. So there are fifty thousand genes for sneezing in elevators—which are also fifty thousand genes for liking blue double-breasted epauletted shirts, using Vitalis hair tonic, wearing seven rings, and all the rest. The reason is that the relationship between particular genes and particular psychological traits is doubly indirect. First, a single gene does not build a single brain module; the brain is a delicately layered soufflé in which each gene product is an ingredient with a complex effect on many properties of many circuits. Second, a single brain module does not produce a single behavioral trait. Most of the traits that capture our attention emerge out of unique combinations of kinks in many different modules. Here is an analogy. Becoming an all-star basketball player requires many physical advantages, like height, large hands, excellent aim, good peripheral vision, lots of fast-twitch muscle tissue, efficient lungs, and springy tendons. Though these traits are probably genetic to a large degree, there does not have to be a basketball gene; those men for whom the genetic slot machine stopped at three cherries play in the NBA, while the more numerous seven-foot klutzes and five-foot sharpshooters go into some other line of work. No doubt the same is true of any interesting behavioral trait like sneezing in elevators (which is no odder than an aptitude for shooting a ball through a hoop with someone’s hand in your face). Perhaps the sneezing-in-elevators gene complex is the one that specifies just the right combination of thresholds and cross-connections among the modules governing humor, reactions to enclosed spaces, sensitivity to the mental states of others such as their anxiety and boredom, and the sneezing reflux.

No one has ever studied heritable variation in language, but I have a strong suspicion of what it is like. I would expect the basic design of language, from X-bar syntax to phonological rules and vocabulary structure, to be uniform across the species; how else could children learn to talk and adults understand one another? But the complexity of language circuitry leaves plenty of scope for quantitative variation to combine into unique linguistic profiles. Some module might be relatively stunted or hypertrophied. Some normally unconscious representation of sound or meaning or grammatical structure might be more accessible to the rest of the brain. Some connection between language circuitry and the intellect or emotions might be faster or slower.

Thus I predict that there are idiosyncratic combinations of genes (detectable in identical twins reared apart) behind the raconteur, the punster, the accidental poet, the sweet-talker, the rapier-like wit, the sesquipedalian, the word-juggler, the owner of the gift of gab, the Reverend Spooner, the Mrs. Malaprop, the Alexander Haig, the woman (and her teenage son!) I once tested who can talk backwards, and the student at the back of every linguistics classroom who objects that
Who do you believe the claim that John saw?
doesn’t sound so bad. Between 1988 and 1992, many people suspected that the chief executive of the United States and his second-in-command were not playing with a full linguistic deck:

And who knows what unrepeatable amalgam of genes creates the linguistic genius?

The elephant’s trunk is six feet long and one foot thick and contains sixty
thousand muscles. Elephants can use their trunks to uproot trees, stack timber, or carefully place huge logs in position when recruited to build bridges. An elephant can curl its trunk around a pencil and draw characters on letter-size paper. With the two muscular extensions at the tip, it can remove a thorn, pick up a pin or a dime, uncork a bottle, slide the bolt off a cage door and hide it on a ledge, or grip a cup so firmly, without breaking it, that only another elephant can pull it away. The tip is sensitive enough for a blindfolded elephant to ascertain the shape and texture of objects. In the wild, elephants use their trunks to pull up clumps of grass and tap them against their knees to knock off the dirt, to shake coconuts out of palm trees, and to powder their bodies with dust. They use their trunks to probe the ground as they walk, avoiding pit traps, and to dig wells and siphon water from them. Elephants can walk underwater on the beds of deep rivers or swim like submarines for miles, using their trunks as snorkels. They communicate through their trunks by trumpeting, humming, roaring, piping, purring, rumbling, and making a crumpling-metal sound by rapping the trunk against the ground. The trunk is lined with chemoreceptors that allow the elephant to smell python hidden in the grass or food a mile away.

Elephants are the only living animals that possess this extraordinary organ. Their closest living terrestrial relative is the hyrax, a mammal that you would probably not be able to tell from a large guinea pig. Until now you have probably not given the uniqueness of the elephant’s trunk a moment’s thought. Certainly no biologist has made a fuss about it. But now imagine what might happen if some biologists were elephants. Obsessed with the unique place of the trunk in nature, they might ask how it could have evolved, given that no other organism has a trunk or anything like it. One school might try to think up ways to narrow the gap. They would first point out that the elephant and the hyrax share about 90% of their DNA and thus could not be all that different. They might say that the trunk must not be as complex as everyone thought; perhaps the number of muscles had been miscounted. They might further note that the hyrax really does have a trunk, but somehow it has been overlooked; after all, the hyrax does have nostrils. Though their attempts to train hyraxes to pick up objects with their nostrils have failed, some might trumpet their success at training the hyraxes to push toothpicks around with their tongues, noting that stacking tree trunks or drawing on blackboards differ from it only in degree. The opposite school, maintaining the uniqueness of the trunk, might insist that it appeared all at once in the offspring of a particular trunkless elephant ancestor, the product of a single dramatic mutation. Or they might say that the trunk somehow arose as an automatic by-product of the elephant’s having evolved a large head. They might add another paradox for trunk evolution: the trunk is absurdly more intricate and well coordinated than any ancestral elephant would have needed.

These arguments might strike us as peculiar, but every one of them has been made by scientists of a different species about a complex organ that that species alone possesses, language. As we shall see in this chapter, Chomsky and some of his fiercest opponents agree on one thing: that a uniquely human language instinct seems to be incompatible with the modern Darwinian theory of evolution, in which complex biological systems arise by the gradual accumulation over generations of random genetic mutations that enhance reproductive success. Either there is no language instinct, or it must have evolved by other means. Since I have been trying to convince you that there is a language instinct but would certainly forgive you if you would rather believe Darwin than believe me, I would also like to convince you that you need not make that choice. Though we know few details about how the language instinct evolved, there is no reason to doubt that the principal explanation is the same as for any other complex instinct or organ, Darwin’s theory of natural selection.

Language is obviously as different from other animals’ communication systems as the elephant’s trunk is different from other animals’ nostrils. Nonhuman communication systems are based on one of three designs: a finite repertory of calls (one for warnings of predators, one for claims to territory, and so on), a continuous analog signal that registers the magnitude of some state (the livelier the dance of the bee, the richer the food source that it is telling its hivemates about), or a series of random variations on a theme (a birdsong repeated with a new twist each time: Charlie Parker with feathers). As we have seen, human language has a very different design. The discrete combinatorial system called “grammar” makes human language infinite (there is no limit to the number of complex words or sentence in a language), digital (this infinity is achieved by rearranging discrete elements in particular orders and combinations, not by varying some signal along a continuum like the mercury in a thermometer), and compositional (each of the infinite combinations has a different meaning predictable from the meanings of its parts and the rules and principles arranging them).

Even the seat of human language in the brain is special. The vocal calls of primates are controlled not by their cerebral cortex but by phylogenetically older neural structures in the brain stem and limbic systems, structures that are heavily involved in emotion. Human vocalizations other than language, like sobbing, laughing, moaning, and shouting in pain, are also controlled subcortically. Subcortical structures even control the swearing that follows the arrival of a hammer on a thumb, that emerges as an involuntary tic in Tourette’s syndrome, and that can survive as Broca’s aphasics’ only speech. Genuine language, as we saw in the preceding chapter, is seated in the cerebral cortex, primarily the left perisylvian region.

Some psychologists believe that changes in the vocal organs and in the neural circuitry that produces and perceives speech sounds are the
only
aspects of language that evolved in our species. On this view, there are a few general learning abilities found throughout the animal kingdom, and they work most efficiently in humans. At some point in history language was invented and refined, and we have been learning it ever since. The idea that species-specific behavior is caused by anatomy and general intelligence is captured in the Gary Larson
Far Side
cartoon in which two bears hide behind a tree near a human couple relaxing on a blanket. One says: “C’mon! Look at these fangs!…Look at these claws!…You think we’re supposed to eat just honey and berries?”

According to this view, chimpanzees are the second-best learners in the animal kingdom, so they should be able to acquire a language too, albeit a simpler one. All it takes is a teacher. In the 1930s and 1940s two psychologist couples adopted baby chimpanzees. The chimps became part of the family and learned to dress, use the toilet, brush their teeth, and wash the dishes. One of them, Gua, was raised alongside a boy of the same age but never spoke a word. The other, Viki, was given arduous training in speech, mainly by the foster parents’ moulding the puzzled chimp’s lips and tongue into the right shapes. With a lot of practice, and often with the help of her own hands, Viki learned to make three utterances that charitable listeners could hear as
papa, mama
, and
cup
, though she often confused them when she got excited. She could respond to some stereotyped formulas, like
Kiss me
and
Bring me the dog
, but stared blankly when asked to act out a novel combination like
Kiss the dog
.

But Gua and Viki were at a disadvantage: they were forced to use their vocal apparatus, which was not designed for speech and which they could not voluntarily control. Beginning in the late 1960s, several famous projects claimed to have taught language to baby chimpanzees with the help of more user-friendly media. (Baby chimps are used because the adults are not the hairy clowns in overalls you see on television, but strong, vicious wild animals who have bitten fingers off several well-known psychologists.) Sarah learned to string magnetized plastic shapes on a board. Lana and Kanzi learned to press buttons with symbols on a large computer console or point to them on a portable tablet. Washoe and Koko (a gorilla) were said to have acquired American Sign Language. According to their trainers, these apes learned hundreds of words, strung them together in meaningful sentence, and coined new phrases, like
water bird
for a swan and
cookie rock
for a stale Danish. “Language is no longer the exclusive domain of man,” said Koko’s trainer, Francine (Penny) Patterson.

These claims quickly captured the public’s imagination and were played up in popular science books and magazines and television programs like
National Geographic, Nova, Sixty Minutes
, and
20/20
. Not only did the projects seem to consummate our age-old yearning to talk to the animals, but the photo opportunities of attractive women communing with apes, evocative of the beauty-and-the-beast archetype, were not lost on the popular media. Some of the projects were covered by
People, Life
, and
Penthouse
magazines, and they were fictionalized in a bad movie starring Holly Hunter called
Animal Behavior
and in a famous Pepsi commercial.

Many scientists have also been captivated, seeing the projects as a healthy deflation of our species’ arrogant chauvinism. I have seen popular-science columns that list the acquisition of language by chimpanzees as one of the major scientific discoveries of the century. In a recent, widely excerpted book, Carl Sagan and Ann Druyan have used the ape language experiments as part of a call for us to reassess our place in nature:

This well-meaning but misguided reasoning could only have come from writers who are not biologists. Is it really “humility” for us to save species from extinction because we think they are like us? Or because they seem like a bunch of nice guys? What about all the creepy, nasty, selfish animals who do not remind us of ourselves, or our image of what we would like to be—can we go ahead and wipe them out? And Sagan and Druyan are no friends of the apes if they think the reason we should treat the apes fairly is that they can be taught human language. Like many other writers, Sagan and Druyan are far too credulous about the claims of the chimpanzee trainers.

People who spend a lot of time with animals are prone to developing indulgent attitudes about their powers of communication. My great-aunt Bella insisted in all sincerity that her Siamese cat Rusty understood English. Many of the claims of the ape trainers were not much more scientific. Most of the trainers were schooled in the behaviorist tradition of B. F. Skinner and are ignorant of the study of language; they latched on to the most tenuous resemblance between chimp and child and proclaimed that their abilities are fundamentally the same. The more enthusiastic trainers went over the heads of scientists and made their engaging case directly to the public on the
Tonight Show
and
National Geographic
. Patterson in particular has found ways to excuse Koko’s performance on the grounds that the gorilla is fond of puns, jokes, metaphors, and mischievous lies. Generally the stronger the claims about the animal’s abilities, the skimpier the data made available to the scientific community for evaluation. Most of the trainers have refused all requests to share their raw data, and Washoe’s trainers, Beatrice and Alan Gardner, threatened to sue another researcher because he used frames of one of their films (the only raw data available to him) in a critical scientific article. That researcher, Herbert Terrance, together with the psychologists Lara Ann Petitto, Richard Sanders, and Tom Bever, had tried to teach ASL to one of Washoe’s relatives, whom they named Nim Chimpsky. They carefully tabulated and analyzed his signs, and Petitto, with the psychologist Mark Seidenberg, also scrutinized the videotapes and what published data there were on the other signing apes, whose abilities were similar to Nim’s. More recently, Joel Wallman has written a history of the topic called
Aping Language
. The moral of their investigation is: Don’t believe everything you hear on the
Tonight Show
.

To begin with, the apes did
not
“learn American Sign Language.” This preposterous claim is based on the myth that ASL is a crude system of pantomimes and gestures rather than a full language with complex phonology, morphology, and syntax. In fact the apes had not learned
any
true ASL signs. The one deaf native signer on the Washoe team later made these candid remarks: