The following is a summary of language acquisition being a controversy in the scientific world. It tries to find answer whether innate capability or social interaction is effective in language acquisition. It voices both sides and gives sound evidence. On one side Chomsky, Gardner and others on the other side Piaget and Clark and others. I want to share this clear explanation of language acquisition with those interested in linguistics.
Nature vs. Nurture:
The Miracle of Language
by Malia Knezek
Why do some children build towers with blocks, cry when they scrape their knees, and shout, "Choo-choo mine!" when a sibling takes away their favorite toy train? Why are some children able to perform entire piano concertos or master complex mathematical concepts, while others cannot even learn to communicate in the normal way? In short, why do humans behave the way they do? With the exception of identical twins, each new human being receives a novel combination of genes divided among forty-six chromosomes. Undoubtedly, this genetic material provides the basis for growth and development and, in doing so, places certain restrictions on the new infant. If the limiting action of genes seems disputable, think of how many people you know who grow to heights of more than twenty feet tall, live longer than two hundred years, or can run faster than a cheetah. My guess would be not many!
Controversy does arise, however, when one tries to examine the extent of genetic influence on human behavior. Just how many of our abilities and shortcomings are innate in nature, and how many are acquired through our interactions with the environment? This debate has been going on for centuries, and popular attitudes have varied greatly throughout this time. At one extreme, we have John Locke's idea of "tabula rasa," which proposes that the minds of newborn infants are blank slates that will be differentiated and altered only through sensory experience. Modern biological determinism represents the other extreme. In its strictest form, this ideology suggests that behaviors are inherent and innate, resulting from the expression of genes. Most intellectuals subscribe to a view somewhere between these two extremes, on the gradient of a controversy that is still a hot topic of debate in many intellectual fields.
One particularly interesting field within the nature-nurture debate that has drawn heated testimony from both sides is language acquisition. How much of our ability to produce and comprehend language is programmed into our genes, and how much do we acquire only with environmental stimulus? Obviously, language cannot be completely genetic. Humans speak a wide variety of different languages, and very young children of any race or ethnic background can learn to speak and understand any of these if exposed to appropriate models at the proper time in development. Similarly, children cannot learn to speak a public language without this critical exposure. However, all humans use language in one form or another, and psychologists and linguists have noted many cross-lingual universals both in how children acquire language and in the inherent characteristics of the languages themselves. Therefore, as is the case with most aspects of human behavior, the truth most likely lies in some combination of nature and nurture.
The ability to use language is a very important part of human cognition. In fact, some would argue that it is this ability which distinguishes us from other animals. Regardless of one's view of the capability of animals to use language or language-like symbols, the fact that humans have language abilities far superior to those of other animals cannot be ignored. Despite the ubiquity of human linguistic ability, pinning down exactly how language helps us and how we use it is not at all a straightforward task. One obvious use for public language is to communicate one�s thoughts to other people. In fact, this may seem like the only, or at least the most important, use of our linguistic abilities. However, both Howard Gardner and Andy Clark stress other uses. Gardner, for example, lists four discrete uses for public language in his Frames of Mind: The Theory of Multiple Intelligences:
People use language to induce action in other people. Examples of this might include a child asking a parent to hand him a toy that is on a high shelf or a boss sending a memo out to his employees asking them to hand in budget drafts by next Wednesday.
Language can be used as a tool by one individual to help that individual remember things. In this way, language expands cognitive abilities that are already present in the human brain. For example, a child may not be able to remember how many days are in December or May, but by learning the rhyme that begins, "Thirty days hath September�" he will easily be able to store these facts in memory. Wearing nametags at a conference and making oral or written shopping lists are other examples of using language to aid memory.
The third use of language involves the transfer of explanations or knowledge from one person to another. For example, the parent teaching his child how to tie his shoes and the professor giving a lecture on ionic bonding are both using language to share their knowledge with another person. It is this use that can lead to cultural evolution, which will be discussed later in this paper.
The fourth discrete use of language is to talk about language itself, or as Gardner states, "to use language to reflect upon language, to engage in �metalinguistic� analysis" (78). A child asking his father what the word "wish" means and a linguist examining the syntactic rules of various languages are both using this type of "metalinguistic analysis."
Gardner acknowledges the wide variety of ways in which we use language, but he believes that they all fit into one of these four categories (78). In his book entitled Being There: Putting Brain, Body, and World Together Again, Andy Clark agrees that language is not solely a tool for communicating thoughts or ideas. He describes the uses of language in more general terms than Gardner. To borrow a fitting analogy from Clark�s book, language is a tool built for use by humans, just as is a pair of scissors. "Just as scissors enable us to exploit our basic manipulative capapcities to fulfill new ends, language enables us to exploit our basic cognitive capacities of pattern recognition and transformation in ways that reach out to new behavioral and intellectual horizons" (193-194). In other words, scissors take the manipulating abilities of human hands and use them to produce a skill that normally could not be accomplished by a human being: namely, cutting a fairly straight line through a piece of paper. Like these scissors, public language takes human abilities that already exist--this time cognitive rather than manipulative in nature--and expounds upon these to give this human-plus-tool combination abilities that were not achievable by the human (or the tool) alone (Clark 193-194). The use of language as an aid to memory, which Gardner lists as one of the four main uses, is an example of this type of ability-enhancement, as is the existence of technical vocabularies in such disciplines as math and physics. Can you imagine, for example, trying to calculate the correct trajectory angle at which to launch a space shuttle without having words to express such concepts as "trajectory," "angle," "force," "velocity," etc.? Such a feat would be near impossible.
Thus, there is general agreement on the importance of language in human cognition, and even in the different ways we use this necessary skill. The ability to use language sets humans apart from other animals and accounts, at least partly, for the uniqueness of our cognitive profile. We would definitely be a very different species were it not for this awesome skill. The question now is: How did we develop this unique ability?
Howard Gardner, along with Noam Chomsky and many others, believes that parts of the brain have evolved over time specifically for the purpose of producing and understanding language. Thinkers such as Andy Clark and Jean Piaget, on the other hand, believe that public language utilizes brain structures and psychological functions that were already present before the development of this important tool. In the first ("nature") school of thought, linguistic abilities have developed over time as a result of Darwinian evolution. In the conflicting ideology (a "nurture" position), there is no innate linguistic ability; and linguistic evolution occurs as a result of learning and cultural evolution, which will be explained in greater detail below, rather than through natural selection. The beliefs do overlap; and oftentimes the proponents of one side argue against what they suppose the other side would believe, when in fact the other side subscribes to no such ideology. For example, the nature proponents argue that human brains are biologically different from the brains of other animals; and that at least part of this diference is due to innate, inherited differences in genes. However, they really need not spend time arguing for this point because the nurture proponents do not, in actuality, disagree with the fact. They also believe that genetic factors are responsible for some of the differences between the brains of humans and those of other animals. The disagreement lies only in how different our brains are from those of other animals, and how much of this difference can be attributed to genetic variances.
Similarly, both sides agree that language draws from and influences other thought processes. However, there is a controversy centered around the extent of this interaction. Nature proponents see language as a very autonomous ability, while nurture proponents tend to see it as more inseparable from other, general cognitive abilities. (For more information on how language influences thought, please see "Something to Talk About" by Brian Skotko.) Do the only disagreements, then, center around questions of degree and extent? It seems, upon cursory examination of the arguments, that the two schools of thought agree on almost all basic tenets of language use, and disagree only on the exact recipe for combining these tenets. This is not the case, however, as true disagreement does exist on some fundamental issues.
First of all, Chomsky, Gardner, and others of similar ideologies believe that infants are born with a significant prewired knowledge of how languages work and how they do not work. Views within this group vary slightly, but they all hold to this basic tenet and cite ample evidence in defense of this view. These proponents of the innateness of linguistic ability also believe that the genetic basis for language came about as the result of Darwinian evolution and by an extension of the "survival of the fittest" argument. Again, individual views vary slightly, but all supporters of this school of thought see language as a product of Darwinian evolution (Gardner 90-91).
On the other hand, Piaget, Clark, and others see the newborn as possesing only a few basic cognitive abilities. The more specific abilities we see in the developing child, they argue, are due to interactions with the environment and are independent of any inheritable code found in the genes. They place language skills in this category, and so they disagree completely with Chomsky�s assertion that humans inherit certain linguistic knowledge (Gardner 80). In addition, proponents of the Nurture ideology view public language as a tool constructed by people for use by people, and they believe its development is due to cultural evolution, a completely different mechanism for change (Clark 200-213).
Perhaps it is worth taking a few moments to describe the differences between Darwinian evolution and cultural evolution. Most people are familiar with the tenets of Darwinian evolution as proposed by Charles Darwin in his Origin of the Species, and as expanded upon by numerous scientists since then. In this type of evolution, natural selection or "survival of the fittest" results in actual changes in the gene frequency of a species. These changes are innate and inheritable, passed down from one generation to the next by means of biological reproduction. This type of evolution is very slow, and even minor changes in a species tend to take thousands or even millions of years to occur.
Cultural evolution, like Darwinian evolution, brings about changes within the human species. However, these changes occur at a much faster rate and by different mechanisms. Whereas traits in "Darwinian" evolution are passed from one generation to the next through genes only, without regard to what progress one generation has made or what it has learned during its lifetime, traits in cultural or "Lamarckian" evolution are passed on through language from one generation to the next. This means that progress made by one generation can be selectively passed on to the next, which does not occur with random genetic mutations. The focus and ease of transfer characteristic of cultural evolution lead to changes that takes place at such a fast rate that the effects of Darwinian evolution, in comparison, are practically negligible. As scientist Stephen Jay Gould remarks, "While the gene for sickle-cell anemia declines in frequency among black Americans, we have invented the railroad, the automobile, radio and television, the atom bomb, the computer, the airplane and spaceship." Clearly, cultural evolution is a distinct process from Darwinian evolution and accounts for many changes in human behavior (324).
"Nurture" advocates in the language debate believe that humans invented language as they did computers through the process of cultural evolution. Again, subscribers to this school of thought have gathered much evidence in support of their theories. Indeed, determining which of these two theories better describes human linguistic ability will require careful examination of the arguements and evidence, and even after such examination will nonetheless prove to be a difficult task.
THE "LANGUAGE FACULTY"
As mentioned before, linguist Noam Chomsky suggests that humans are born with an innate knowledge of language, and he calls this knowledge the "language faculty." He invisions this "language faculty" as a biologically autonomous system in the brain that "has an initial state which is genetically determined, like. . . the kidney, the circulatory system, and so on" (13).
Chomsky supports his claim with several lines of evidence. For one thing, he argues that all humans (except, of course, those suffering from a language-related pathology) understand certain ambiguities of language the same way. For example, take the expression "brown house," which could be expressed in another language as well as English. Upon hearing this expression, any human would have certain understandings that were not expressed with language explicitly. For example, even children realize that this expression contains two separate words with separate meanings, quite a feat when considering that the spoken phenomes generally run together. When spoken in English, a listener will know that the two words contain the same vowel sound. More surprisingly, when this phrase is spoken in any language, the listener will understand that the speaker is referring to a house that is brown on the outside. This is remarkable, because houses can just as easily have brown interiors, but listeners never have to ask which surface (inner or outer) the color is naming (Chomsky 20-21). Chomsky argues that this type of linguistic knowledge must be innate since every healthy human makes the same assumptions. He also suggests that knowledge such as that described above must exist in the language faculty in the brain.
Linguist M. Y. Liberman describes other characteristics found in every spoken human language. First, all of these languages have very large vocabularies consisting of words "whose articulatory/acoustic definition is mediated by a phonological system." Second, all languages have a grammatical system that governs the way in which these words are combined to express meaning. Third, all languages change throughout time with new words being added and old ones being dropped or changed continuously (qtd. in Studdert-Kennedy 8).
Anthropologist Donald E. Brown describes even more detailed aspects of language that all humans share. First, in any given language words can exist that are the equivalent of "good," "wide," and "deep." In some languages, opposite words (bad, narrow, and shallow) exist also. In others, however, the opposites are formed with a negating word and the original juxtaposed (not good, not wide, not deep). The surprising finding is that in no language does the negation go the other way ("not bad" to express "good," etc.). Does this happen because the expression of such concepts as good, wide, and deep lies in the language faculty and is innate in all humans? Chomsky would say that it does. He would also cite other universals listed by Brown, including the fact that all languages contain nouns, verbs, and possessive formations, as well as the fact that poetry around the world has lines that last about three seconds in between pauses, as evidence of a "language faculty" genetically present in all human brains (Brown 132).
Another fact that Chomsky believes supports his theory of the "language faculty" involves comparing humans to other species. Not only do we have a linguistic ability much superior to that of other animals, but the rules we have regarding language and symbols in general cannot be found in any other species (Chomsky 13). For example, if one were to teach a chimpanzee signs that meant "brown house," he would not have all the innate knowledge described above which is present in all humans. In addition, this process would involve much teaching and learning before a chimp could learn these signs; whereas humans acquire such knowledge with little or no conscious effort taking place.
This brings us to another fact that provides strong evidence for Chomsky's theory: that all normal children acquire language in the same way. Chomsky prefers the term "language acquisition" rather than "language learning," because he sees this process as a maturation of the language faculty (much like the growth of a heart or kidney) rather than a learning process (Chomsky 13). Gardner also describes this very process in his chapter on linguistic intelligence. Infants begin babbling not too long after birth, and the sounds produced during this period contain the basic sounds they hear spoken around them as well as phenomes not present in their native tongue. This is strong evidence for an innate language faculty. By the time the child turns two years old, he or she will speak single words in the native language, and soon thereafter, will begin to form very simple, two-word "sentences." These word pairs are meaningful and often novel combinations of words known by the child. Examples may include "drink milk," "byebye Daddy," and "doggy run." By the age of three, these two-word utterances grow in length and complexity, so that the three-year-old child can utter sentences of several words long, even including questions, negations, and clauses. These sentences often have grammatical errors (which can be explained by overgeneralization and remain consistent throughout speakers of a single language), such as in the example, "I no watch T.V. no more." By the time the child is four or five years old, he no longer makes these grammatical mistakes; and he "can speak with considerable fluency in ways that closely approximate adult syntax" (Gardner 79).
Three aspects of this form of language acquisition are of interest in light of Chomsky's theory. That all children follow this development regardless of the language they speak supports Chomsky's claim of an inate language organ that is maturing through this process. Secondly, during the babbling stage, babies produce phenomes they have never heard, from a variety of different languages spoken around the world. Chomsky believes that this is due to the fact that the "language faculty" already contains knowledge of all the sounds that can be produced in any natural spoken language, more evidence for extensive innate language knowledge. Third, normally-developed four-year-olds are already able to "come up with appealing figures of speech (comparing a foot falling asleep to bubbling ginger ale); tell short stories� alter their speech register depending upon whether they are addressing adults, peers, or toddlers younger than themselves, and even engage in simple metalinguistic banter." The latter includes asking such questions as "What does X mean?" and "Should I say X or Y?" These feats are truly remarkable, and as of yet no machine or computer program has even come close to reproducing them (Gardner 80). According to Chomsky, young children would not be able to accomplish such feats without the aid of an innate knowledge system based on language.
The biology of the brain can also support Chomsky's theory. Almost all right-handed humans have language centers located in the left hemisphere of the brain. This left hemisphere is larger and structurally different from the right hemisphere, an asymmetry that can be traced to the Neanderthal man, but is not seen in monkeys (Gardner 90). There are several specialized regions in the left hemisphere that are used for various language tasks, such as Broca's area for producing language and Wernicke's area for comprehending language spoken by others. Lesions to various regions of the brain cause very distinctive aphasias, or language problems; and the same area causes the same aphasia across the species. For more information on the neurobiology of language and the specific aphasias, please see Bora Lee's paper entitled ??? The evidence gleaned from studies of aphasic patients supports Chomsky's theory by pinpointing various areas of the brain that seem to be a part of this innate "language faculty."
The final evidence for Chomsky's view of language comes from evolutionary studies. As mentioned earlier, brain asymmetry linked to the language faculty has been found to exist in Neanderthal man, which means they date back thirty thousand to one hundred thousand years. There is also evidence that this asymmetry may exist even in the great apes, although evidence is not conclusive. Either way, the structural brain regions needed for language have been present in the species long before recorded history, which suggests a gradual evolution of intellectual capacities (Gardner 90). Many intellectuals on the "nature" side of the language debate believe that this could explain how humans acquired their language abilities through gradual evolution. Chomsky, however, has a different view. He believes that our language capabilities could not have evolved gradually; and, instead, he proposes that the entire language faculty came in one evolutionary step (Gardner 91).
Regardless of their views on the specifics of evolution, all "nature" advocates believe that human lingual ability results from an innate, inherited "language faculty" through which lingual information is passed on from one generation to the next.
LANGUAGE AS AN ARTIFACT
Those who believe that language is learned through intellectual processes common to all learning and who do not believe in an innate "language faculty" explain the evidence presented above in another way. According to proponents of the "nurture" theory, humans are much more advanced than other animals because they are able to use language, rather than the other way around. The mechanisms that make this possible will be explained in the next few pages.
One major type of evidence that Chomsky and others who believe in an innate language faculty often cite is the universal characteristics of language itself and of language acquisition in humans. But does the fact that all humans exhibit a certain behavior really prove that that behavior is due to the genetic code of the human? As Donald E. Brown explains in his book entitled Human Universals, this is not necessarily the case. "[U]niversals form a heterogeneous set. A great many, for example, seem to be inherent in human nature. Some are cultural conventions that have come to have universal distribution" (4).
To understand how a behavior exhibited by all humans can be due to culture rather than genetics, consider the example of cooking food. All humans cook their food, but there is no "cooking gene" that genetically programs us to do this. Rather, cooking was discovered by some human and found to be so beneficial that every human who came in contact with the procedure adopted it. In this way, cooking spread across the earth and became a universal, even without a genetic basis.
Could the universals found in language be explained in the same way? Language certainly seems to be beneficial enough to have spread this way from human to human and culture to culture. However, this does not explain why we have special parts of the brain dedicated to language or why humans can communicate through language while other animals cannot.
In order to understand how a culturally based model of language could account for these facts, it is important to examine how new models are being used to explain the brain and human behavior. The brain, above all else, is an organ whose purpose is to manipulate the behavior of the body in an environment to secure survival. This is true of all species from the snail to the human. It has been shown experimentally that experience causes structural and chemical changes at the synapses between neurons which means that learning takes place in the connections between neurons. If, for example, a dog finds that jumping over a fence allows him to eat some meat barbecuing in the neighbor's yard, and if this behavior gets this reward several times, then the connections between his neurons will strengthen in the path that goes from smelling meet to jumping the fence. If, however, the dog tries to jump the fence one day and gets shocked by an electrical wire, the weights of connections will become weaker. If this happens several times, then the neuronal path between smelling meat and jumping the fence will have a strong inhibitory connection, so that the dog no longer performs this behavior.
How does this relate to a human brain producing and understanding language? Well, suppose a baby finds that if he produces the sound "wa-wa" he will receive a drink of water. The neuronal connections between his feeling of thirst and his speaking the sound "wa-wa" will be strongly excitatory, and he will have learned to communicate. If, however, his mother decides to break him from the habit of baby-talk and only gives him water when he pronounces the entire word "water," then the connections between thirst and "wa-wa" will become inhibitory and a new neural path, between thirst and "water," will become more excitatory.
This still does not explain why so many people have the same assumptions when hearing the phrase "brown house" or why language functions are so specific to regions of our brains. To understand these phenomena, one must realize that humans use language as "a tool that alters the nature of the computational tasks involved in various kinds of problem solving" (Clark 193). To return to the scissors analogy from before, humans created scissors in order to increase the scope of our manual skills to include cutting straight lines. Similarly, we created language to increase the scope of our mental abilities. Just as scissors have one part for manipulating the environment (the blades) and one for making them easier to hold (the handles), language also performs a double function. Not only must language be able to cause changes in the environment (or in our own thinking, such as when we write a grocery list to remember what we need to buy), but the language we use must also fit the intellectual abilities we already have. Thus, language as a tool would not be helpful if it demanded more of our intellect than it provided in benefits. Because of this fact, language is constantly evolving in two directions--to better express our ideas and manipulate the world and to better fit the structures and functions of our various brain regions (Clark 193-194). If, for example, the area in the left hemisphere that we call Broca's area was already well-adapted to finding structure and rules in a random input of stimulus, then this area would naturally be where the grammatical structure of language is stored; and a lesion to this area would then make it hard for the subject to produce gramatically meaningful speech. This could explain the assymetry of the brain and the cases of aphasia that show the brain's specificity. Just because all humans have a Broca's area that houses the faculties for producing grammatical speech does not necessarily mean that Broca's area evolved for this purpose.
What about the fact that other animals do not have similar language capabilities? Obviously, if you place a snail (or even a monkey) in a situation where it comes in contact with many models of human speech, it will still not learn to use language. This obviously involves some innate difference between humans and other animals, which means that we have genes that are different from those of other animals. However, the difference could just lie in our vocal tracts and our hearing ability. Chances are that this is not the case since other animals do not use any other form of language (i.e. sign language) even though they have the physiological capabilities. Most likely, there are some differences between human brains and those of other animals, though the differences need not be nearly as pronounced as Chomsky and others believe they are. As explained above, the language tool that we have invented gives us many mental capabilities we would not have otherwise, including thinking about thinking. Thus, a tiny evolutionary difference in our brain could have given us the ability to invent language, an artifact that may make possible not only higher-order thinking exhibited by humans, but perhaps even the consciousness that we so dearly treasure (Clark 208-209).
So all we can say for sure is that language, like so many other aspects of human behavior, has proven to be the product of nature and nurture working together. This amazing human ability to communicate through language is both the result and the cause of our uniqueness as human beings. Language is a tool indeed: Simple enough for a child to effortly grasp, yet so complex that we may never completely understand just how genetics and experience interact to produce this most integral human trait.
Brown, Donald E. Human Universals. New York: McGraw-Hill, Inc., 1991.
Chomsky, Noam. Powers and Prospects: Reflections on Human Nature and the Socail Order. Boston: South End Press, 1996.
Clark, Andy. Being There: Putting Brain, Body, and World Together Again. Cambridge, Mass.: The MIT Press, 1997.
Gardner, Howard. Frames of Mind: the Theory of Multiple Intelligences. New York: Harper Collins, 1983.
Gould, Stephen Jay. The Mismeasure of Man. New York: W.W. Norton & Company, 1981.
Studdert-Kennedy, Michael, ed. Psychobiology of Language. Cambridge, Mass: The MIT Press, 1983.