The Language Instinct: How the Mind Creates Language

  By the time children are of nursery school and kindergarten age, they display a subtle understanding that living things fall into kinds with hidden essences. The psychologist Frank Keil has challenged children with pixilated questions like these:

  Doctors took a raccoon [shows picture of a raccoon] and shaved away some of its fur. They dyed what was left all black. Then they bleached a single stripe all white down the center of its back. Then, with surgery, they put in its body a sac of super smelly yucky stuff, just like a skunk has. When they were all done, the animal looked like this [shows picture of skunk]. After the operation, was this a skunk or a raccoon?

  Doctors took a coffeepot that looked like this [shows picture of a coffeepot]. They sawed off the handle, sealed the top, took off the top knob, closed the spout, and sawed it off. They also sawed off the base and attached a flat piece of metal. They attached a little stick, cut a window in it, and filled the metal container with birdfood. When they were done, it looked like this [shows picture of a birdfeeder]. After the operation, was this a coffeepot or a birdfeeder?

  Doctors took this toy [shows picture of a wind-up bird]. You wind it up with a key, and its mouth opens and a little machine inside plays music. The doctors did an operation on it. They put on real feathers to make it nice and soft and they gave it a better beak. Then they took off the wind-up key and put in a new machine so that it flapped its wings and flew, and chirped [shows picture of a bird]. After the operation, was it a real bird or a toy bird?

  For artifacts like a coffeepot turning into a bird feeder (or a deck of cards turning into toilet paper), the children accepted the changes at face value: a birdfeeder is anything that is meant to feed birds, so that thing is a birdfeeder. But for natural kinds like a raccoon turning into a skunk (or a grapefruit turning into an orange), they were more resistant; there was some invisible raccoonhood lingering in the skunk’s clothing, and they were less likely to say that the new creature was a skunk. And for violations of the boundary between artifacts and natural kinds, like a toy turning into a bird (or a porcupine turning into a hairbrush), they were adamant: a bird is a bird and a toy is a toy. Keil also showed that children are uncomfortable with the idea of a horse that has cow insides and cow parents and cow babies, even though they have no problem with a key that is made of melted-down pennies and is then melted down to make pennies again.

  And of course adults from other cultures have the same sorts of intuitions. Illiterate rural Nigerians were given the following kind of question:

  Some students took a pawpaw [shows picture of a pawpaw] and stuck some green, pointed leaves on the top. Then they put small, prickly patches all over it. Now it looks like this [shows picture of a pineapple]—is it a pawpaw or a pineapple?

  A typical response was, “It’s a pawpaw, because a pawpaw has its own structure from heaven and a pineapple its own origin. One cannot turn into the other.”

  Little children also sense that animal kinds fall into larger categories, and their generalizations follow the similarity defined by category membership, not mere similarity of appearance. Susan Gelman and Ellen Markman showed three-year-old children a picture of a flamingo, a picture of a bat, and a picture of a blackbird, which looked a lot more like the bat than like the flamingo. They told the kids that a flamingo feeds its babies mashed-up food but a bat feeds its babies milk, and asked them what the blackbird feeds its babies. With no further information, children went by appearances and predicted milk. But all it took was a mention that flamingos and blackbirds were birds, and the children lumped them together and predicted mashed-up food.

  And if you really doubt that we have botany instincts, consider one of the oddest of human motives: looking at flowers. A huge industry specializes in breeding and growing flowers for people to use in decorating dwellings and parks. Some research shows that bringing flowers to hospital patients is more than a warm gesture; it may actually improve the patient’s mood and recovery rate. Since people rarely eat flowers, this diversion of effort and resources seems inexplicably frivolous. But if we evolved as intuitive botanists, it makes some sense. A flower is a microfiche of botanical information. When plants are not in bloom, they blend into a sea of green. A flower is often the only way to identify a plant species, even for a professional taxonomist. Flowers also signal seasons and terrains of expected bounty and the exact locations of future fruits and seeds. A motive to pay attention to flowers, and to be where they are, would obviously have been useful in environments where there were no year-round salad bars.

  Intuitive biology is, of course, very different from what professors of biology do in their laboratories. But professional biology may have intuitive biology at its foundation. Folk taxonomy was obviously the predecessor to Linnaean taxonomy, and even today, professional taxonomists rarely contradict indigenous tribes when they classify the local species. The intuitive conviction that living things have a hidden essence and are governed by hidden processes is clearly what impelled the first professional biologists to try to understand the nature of plants and animals by bringing them into the laboratory and putting bits of them under a microscope. Anyone who announced he was trying to understand the nature of chairs by bringing them into a laboratory and putting bits of them under a microscope would surely be dismissed as mad, not given a grant. Indeed, probably all of science and mathematics is driven by intuitions coming from innate modules like number, mechanics, mental maps, even law. Physical analogies (heat is a fluid, electrons are particles), visual metaphors (linear function, rectangular matrix), and social and legal terminology (attraction, obeying laws) are used throughout science. And if you will allow me to sneak in one more offhand remark that really deserves a book of its own, I would guess that most other human “cultural” practices (competitive sports, narrative literature, landscape design, ballet), no matter how much they seem like arbitrary outcomes of a Borgesian lottery, are clever technologies we have invented to exercise and stimulate mental modules that were originally designed for specific adaptive functions.

  So the language instinct suggests a mind of adapted computational modules rather than the blank slate, lump of wax, or general-purpose computer of the Standard Social Science Model. But what does this view say about the secular ideology of equality and opportunity that the model has provided us? If we abandon the SSSM, are we forced to repugnant doctrines like “biological determinism”?

  Let me begin with what I hope are obvious points. First, the human brain works however it works. Wishing for it to work in some way as a shortcut to justifying some ethical principle undermines both the science and the ethics (for what happens to the principle if the scientific facts turn out to go the other way?). Second, there is no foreseeable discovery in psychology that could bear on the self-evident truth that ethically and politically, all people are created equal, that they are endowed with certain inalienable rights, and that among these are life, liberty, and the pursuit of happiness. Finally, radical empiricism is not necessarily a progressive, humanitarian doctrine. A blank slate is a dictator’s dream. Some psychology textbooks mention the “fact” that Spartan and samurai mothers smiled upon hearing that their sons fell in battle. Since history is written by generals, not mothers, we can dismiss this incredible claim, but it is clear what purposes it must have served.

  With those points out of the way, I do want to point out some implications of the theory of cognitive instincts for heredity and humankind, for they are the opposite of what many people expect. It is a shame that the following two claims are so often confused:

  Differences between people are innate.

  Commonalities among all people are innate.

  The two claims could not be more different. Take number of legs. The reason that some people have fewer legs than others is 100% due to the environment. The reason that all uninjured people have exactly two legs (rather than eight, or six, or none) is 100% due to heredity. But claims that a universal human nature is innate are often run together with claims that diff
erences between individuals, sexes, or races are innate. One can see the misguided motive for running them together: if nothing in the mind is innate, then differences between people’s minds cannot be innate; thus it would be good if the mind had no structure because then decent egalitarians would have nothing to worry about. But the logical inverse is false. Everyone could be born with identical, richly structured minds, and all differences among them could be bits of acquired knowledge and minor perturbations that accumulate through people’s history of life experiences. So even for people who, inadvisably in my view, like to conflate science and ethics, there is no need for alarm at the search for innate mental structure, whatever the truth turns out to be.

  One reason innate commonalities and innate differences are so easy to confuse is that behavior geneticists (the scientists who study inherited deficits, identical and fraternal twins, adopted and biological children, and so on) have usurped the word “heritable” as a technical term referring to the proportion of variation in some trait that correlates with genetic differences within a species. This sense is different from the everyday term “inherited” (or genetic), which refers to traits whose inherent structure or organization comes from information in the genes. Something can be ordinarily inherited but show zero heritability, like number of legs at birth or the basic structure of the mind. Conversely, something can be not inherited but have 100% heritability. Imagine a society where all and only the red-haired people were made priests. Priesthood would be highly “heritable,” though of course not inherited in any biologically meaningful sense. For this reason, people are bound to be confused by claims like “Intelligence is 70% heritable,” especially when the newsmagazines report them in the same breath (as they inevitably do, alas) with research in cognitive science on the basic workings of the mind.

  All claims about a language instinct and other mental modules are claims about the commonalities among all normal people. They have virtually nothing to do with possible genetic differences between people. One reason is that, to a scientist interested in how complex biological systems work, differences between individuals are so boring! Imagine what a dreary science of language we would have if instead of trying to figure out how people put words together to express their thoughts, researchers have begun by developing a Language Quotient (LQ) scale, and busied themselves by measuring thousands of people’s relative language skills. It would be like asking how lungs work and being told that some people have better lungs than others, or asking how compact disks reproduce sound and being given a consumer magazine that ranked them instead of an explanation of digital sampling and lasers.

  But emphasizing commonalities is not just a matter of scientific taste. The design of any adaptive biological system—the explanation of how it works—is almost certain to be uniform across individuals in a sexually reproducing species, because sexual recombination would fatally scramble the blueprints for qualitatively different designs. There is, to be sure, a great deal of genetic diversity among individuals; each person is biochemically unique. But natural selection is a process that feeds on that variation, and (aside from functionally equivalent varieties of molecules) when natural selection creates adaptive designs, it does so by using the variation up: the variant genes that specify more poorly designed organs disappear when their owners starve, get eaten, or die mateless. To the extent that mental modules are complex products of natural selection, genetic variation will be limited to quantitative variations, not differences in basic design. Genetic differences among people, no matter how fascinating they are to us in love, biography, personnel, gossip, and politics, are of minor interest to us when we appreciate what makes minds intelligent at all.

  Similarly, an interest in mind design puts possible innate differences between sexes (as a psycholinguist I refuse to call them “genders”) and races in a new light. With the exception of the maleness-determining gene on the Y-chromosome, every functioning gene in a man’s body is also found in a woman’s and vice versa. The maleness gene is a developmental switch that can activate some suites of genes and deactivate others, but the same blueprints are in both kinds of bodies, and the default condition is identity of design. There is some evidence that the sexes depart from this default in the case of the psychology of reproduction and the adaptive problems directly and indirectly related to it, which is not surprising; it seems unlikely that peripherals as different as the male and female reproductive systems would come with the same software. But the sexes face essentially similar demands for most of the rest of cognition, including language, and I would be surprised if there were differences in design between them.

  Race and ethnicity are the most minor differences of all. The human geneticists Walter Bodmer and Luca Cavalli-Sforza have noted a paradox about race. Among laypeople, race is lamentably salient, but for biologists it is virtually invisible. Eighty-five percent of human genetic variation consists of the differences between one person and another within the same ethnic group, tribe, or nation. Another eight percent is between ethnic groups, and a mere seven percent is between “races.” In other words, the genetic difference between, say, two randomly picked Swedes is about twelves times as large as the genetic difference between the average of Swedes and the average of Apaches or Warlpiris. Bodmer and Cavalli-Sforza suggests that the illusion is the result of an unfortunate coincidence. Many of the systematic differences among races are adaptations to climate: melanin protects skin against the tropical sun, eyelid folds insulate eyes from dry cold and snow. But the skin, the part of the body seen by the weather, is also the part of the body seen by other people. Race is, quite literally, skin-deep, but to the extent that perceivers generalize from external to internal differences, nature has duped them into thinking that race is important. The X-ray vision of the molecular geneticist reveals the unity of our species.

  And so does the X-ray vision of the cognitive scientist. “Not speaking the same language” is a virtual synonym for incommensurability, but to a psycholinguist, it is a superficial difference. Knowing about the ubiquity of complex language across individuals and cultures and the single mental design underlying them all, no speech seems foreign to me, even when I cannot understand a word. The banter among New Guinean highlanders in the film of their first contact with the rest of the world, the motions of a sign language interpreter, the prattle of little girls in a Tokyo playground—I imagine seeing through the rhythms to the structures underneath, and sense that we all have the same minds.

  Notes

  1. An Instinct to Acquire an Art

  Amorous octopuses: adapted from Wallace, 1980. Cherry stains: Parade magazine, April 5, 1992, p. 16. All My Children: adapted from Soap Opera Digest, March 30, 1993.

  Horse graveyard: Lambert & The Diagram Group, 1987. Megafauna extinctions: Martin & Klein, 1984.

  Cognitive science: Gardner, 1985; Posner, 1989; Osherson & Lasnik, 1990; Osherson, Kosslyn, & Hollerbach, 1990; Osherson & Smith, 1990.

  Instinct to acquire an art: Darwin, 1874, pp. 101–102.

  The why of instinctive acts: James, 1892/1920, p. 394.

  Chomsky: Chomsky, 1959, 1965, 1975, 1980a, 1988, 1991; Kasher, 1991.

  Chomsky on mental organs: Chomsky, 1975, pp. 9–11.

  Top ten list: from Arts and Humanities Citation Index; Kim Vandiver, Chairman of the Faculty, MIT, citation for Noam Chomsky’s Killian Faculty Achievement Award, MIT, March 1992.

  Standard Social Science Model: Brown, 1991; Tooby & Cosmides, 1992; Degler, 1991. Challenging Chomsky: Harman, 1974; Searle, 1971; Piatelli-Palmarini, 1980; commentators in Chomsky, 1980b; Modgil & Modgil, 1987; Botha, 1989; Harris, 1993. Putnam on Chomsky: Piatelli-Palmarini, 1980, p. 287.

  2. Chatterboxes

  First contact: Connolly & Anderson, 1987.

  Language is universal: Murdoch, 1975; Brown, 1991.

  No primitive languages: Sapir, 1921; Voegelin & Voegelin, 1977. Plato and swineherds: Sapir, 1921, p. 219.

  Bantu syntax: Bresnan & Moshi, 1988; Bresnan, 1990
. Cherokee pronouns: Holmes & Smith, 1977.

  Logic of nonstandard English: Labov, 1969.

  Putnam on general multipurpose learning strategies: Piatelli-Palmarini, 1980; Putnam, 1971; see also Bates, Thal, & Marchman, 1991.

  Creoles: Holm, 1988; Bickerton, 1981, 1984.

  Sign language: Klima & Bellugi, 1979; Wilbur, 1979.

  Lenguaje de Signos Nicaragüense and Idioma de Signos Nicaragüense: Kegl & Lopez, 1990; Kegal & Iwata, 1989.

  Children acquiring ASL: Petitto, 1988. Adults acquiring language (signed and spoken): Newport, 1990.

  Simon: Singleton & Newport, 1993. Sign languages as creoles: Woodward, 1978; Fischer, 1978. Unlearnability of artificial sign systems: Supalla, 1986.