The Human Journey
Language Development

Language Development


The First Word

The Search for the Origins of Language

Penguin Books, 2008

Pages 123456

Noam Chomsky

Noam Chomsky
Noam Chomsky

In 1957 Noam Chomsky published Syntactic Structure, an examination of language that discussed the grammar of language in an entirely new way. Instead of cataloguing all the words and sounds in a particular language with instructions for putting them together, he argued that a grammar was really a theory of language that should explain as much as it can with as little as possible. In this way, the grammars of language can be compared in the same way as different theories in science can be compared, with the successful theory more fully explaining the phenomenon in question in the most economical way possible.

The best method, he argued, was to collapse all of language into a set of rules, in much the same way that software generates output in a computer, and the rules will generate an entire language. For example, an English sentence can be described as S goes to NP VP meaning that a sentence (S) consists of a noun phrase (NP) and a verb phrase (VP), and NP goes to Det N means that a noun phrase consists of a determiner (Det) and a noun (N). In addition, Chomsky said that the set of language rules could be made smaller and simpler if ways to relate certain sentences to each other were included. As an example he said that “The man read the book” and “The book was read by the man” have a close similarity. Instead of separate rules for each of them, he suggested the more complicated second sentence was derived from the first, calling it a transformation. In this way the relationship between all the simple active sentences of English and their passive versions can be described by just these two simple structures and the transformation rule that links them.

Chomsky viewed language as basically a set of sentences, and the job of grammar is to generate all the allowable sentences and all the possible utterances in a language in much the same way that a chemical theory generates all possible compounds. He dismissed the idea of the evolution of language as a subject that was not interesting, which for a number of years acted as an unofficial ban on research in that direction. Chomsky suggested instead that there was an organ in the brain devoted exclusively to grammar and syntax that generates a universal grammar whereby every child learns early and rapidly to speak the language of the population in which it is born.

Even though he imagined an idealized speaker and hearer as the subjects of his research, in the Chompskyan sense language had little to do with the reality that language overwhelmingly takes place between people. The Chompskyan linguist, studying what was interesting about language, was at the same time discarding any variation in the way a given speaker actually speaks and focused instead on the skeleton of interaction that remained.

It is fair to say that such was the eminence of Chomsky that when he said things like it’s “hard to imagine” as he often did, it was taken to be a truth about the intractable nature of a problem rather than the limits of imagination. As far back as 1973, his critics pounced on the notion being advanced that language had suddenly come into existence as the result of a mutation. Yet Chomsky in no sense advanced this argument, he merely suggested it. And his most damning evaluation of the idea that language was an adaptation was that it was (again) “hard to imagine” a course of selection that could have resulted in language. It is a testament to both his rhetorical skills and the depth of his influence that a strong case could be so widely inferred by others from his highly qualified statements on the topic.

Both sides of the debate about language evolution would agree that for many years Noam Chomsky deemed the evolution of language unworthy of investigation. And then in a paper he published with another researcher in 2002, he seemed to relent on his objection to language evolution, which stirred up controversy and heated discussions among both his supporters and other interested parties that is still in progress.

Sue Savage-Rumbaugh

Sue Savage-Rumbaugh
Sue Savage-Rumbaugh

Given Noam Chomsky’s widely known lack of interest in the subject, theories about language evolution remained for most of the twentieth century the bailiwick of the occasional crackpot and a few brilliant and determined mavericks. Sue Savage-Rumbaugh was a member of the second group. Although the general consensus in linguistics and most of psychology was that language was a monolithic trait possessed only by humans, Savage-Rumbaugh was busy trying to teach another primate how to use it.

Apes are social, emotional, affectionate and smart and need other apes just as humans need other humans. Such similarities between apes and humans, according to Darwin, were likely inherited from a common ancestor. He argued further that the traits we have in common with a closely related species are a matter of shared inheritance rather than an independent, parallel evolution. This knowledge seems obvious in the twenty-first century, but it wasn’t always so.

The idea that human intelligence was a unique phenomenon only began to change in a small way after reports began to circulate from primatologists in the field such as Jane Goodall, the primatologist now well known by the public for her observations of apes. As recently as fifty years ago we knew virtually nothing about the apes or other primates. The years that Goodall and her colleagues spent patiently watching them in the wild provided remarkable insights into the lives of other primates and how like them humans are.

The place in history of Sue Savage-Rumbaugh may be assured. She is the researcher who has most successfully bridged the species gap by teaching apes to understand aspects of language by talking to them and using a picture keyboard to point out pictures of the words they are hearing. She and her colleague, Duane Rumbaugh, take raw material like a chimpanzee or bonobo and see to what extent they can bypass a few million years of evolution. The first generation of language-trained apes had learned to comprehend language, but according to Savage-Rumbaugh, language for them was a one-way street, functioning as a tool for getting what they wanted.

Kanzi
Kanzi

Ape language research, which began in the 1970s, then made an evolutionary leap when Savage-Rumbaugh realized that rather than directly teaching language to apes, the best way to go about it is to teach them indirectly, much as young children learn language by hearing it all around them and interacting with others. She had been teaching language to a female bonobo, the mother of a young male named Kanzi, who was always in the room observing his mother’s lessons. When Savage-Rambaugh finally turned her attention specifically to Kanzi, she was astonished that he spontaneously used the picture keyboard to combine symbols and communicate what he wanted her to do and what he wanted to do next. After that, the younger bonobos were raised in a language-rich environment and picked up words more quickly by regularly being spoken to during feeding, playing, and grooming. Rather than hundreds of repetitions of a word while pointing to the sign for it on the picture board as with the previous teaching procedure, the apes were now first learning words indirectly followed by learning the signs on the board for the words they had heard.

As well as well as developing the comprehension abilities of a 3 to 4 year-old child, the bonobos demonstrate creativity in their manipulation of language. For instance, some of them spontaneously combine single words that they already know to create new words, such as linking “water” and “bird” to form “waterbird,” meaning a duck. Another ape once rushed into a lab to tell the people inside, “Scare outside.” He had just seen a partially anesthetized ape being carried past on a stretcher. Yet another ape that was told to put water on a carrot threw the carrot outside. Thinking the ape had misunderstood, the request was repeated. The ape’s response was to point to the outdoors in a vigorous manner where it was raining.

One of the most important contributions of ape language research is to show that apes not only can learn the rudiments of a language but can also be flexible and creative with their communication, and this opened a window into the problems of language evolution. Then in 1990, Steven Pinker and Paul Bloom opened another window when they published a paper that avoided the question about how much animal language training can teach us about language evolution. They argued instead that not only could language evolution be studied but that it should be studied. While not the first to propose that language evolution was a valid topic of inquiry, their paper touched a ready core of interest that grew and spread.

Steven Pinker and Paul Bloom

Paul Bloom
Paul Bloom

In 1989 Paul Bloom was a twenty-five year old graduate student in the psychology department at MIT doing research in language development in children. His interest in word learning in children had nothing to do with evolution, but he was increasingly bothered by the general agreement that language could not have evolved. Two things happened at once, he said later. A prominent evolutionary psychologist, Leda Cosmides, gave a talk at MIT about the mind and language from an adaptive point of view. Talking with her later, Bloom mentioned a line from Stephen Jay Gould, the influential Harvard evolutionary biologist, that had persuaded him years before. Gould thought there was no reason to favor an adaptionist account of language as opposed to the accepted view that it was an evolutionary accident. Comides disagreed with Gould about evolution, telling Bloom that there were good reasons to believe that something as rich and as complicated as language could indeed have evolved by natural selection. After thinking over what Cosmides had to say, Bloom decided it made sense.

About the same time, a colleague and friend of Bloom, Massimo Piatelli-Palmarini, in the Department of Linguistics and Philosophy published an article on the evolution of cognition and language that presented the Chomskyan view on evolution that language has features that simply cannot be explained in terms of adaptation. Bloom found that he strongly disagreed with Piatelli-Palmarini, although it appeared to Bloom that everyone else at that time was in agreement with his colleague. There was no way to underestimate the influence of Chomsky and Gould on any discussion about language evolution, particularly on those who didn’t independently have an interest in evolutionary biology or evolutionary theory.

Steven Pinker
Steven Pinker

Bloom approached Steven Pinker, at the time a young cognitive scientist in the MIT psychology department and proposed that the two write a paper responding to Piatelli-Palmarini. Pinker’s motivation for agreeing to Bloom’s proposal was the feeling that there was a premature consensus from two charismatic figures, Gould and Chomsky, neither of whom had a sensible argument. There was the Gould-inspired consensus about evolution that said scientists were too quick to apply evolutionary explanations to everything and that at some point in the past our brains had evolved to a complex level and at that level the structure for language was already in place. Gould’s view of evolution was not mainstream within evolutionary biology, but people outside the field were not aware of this. As for the Chomsky view, it was not the case that everyone in child language acquisition or cognitive science in general was a Chomskyan. At the time, Chomsky was a divisive figure with large sectors so in thrall to him that if Chomsky said something about language it must be true, and therefore any disagreement with Chomsky’s theory of language was because you must not understand what he was saying.

Pinker immersed himself in research about evolution, and in 1990 Pinker and Bloom published a paper that ran 70 pages. Their original paper was 20 pages, followed by 37 pages of comments from 31 different sources who read the paper, plus 13 additional pages from Pinker and Bloom in response to these comments. The overwhelming impact on readers of the paper was from the stand that Pinker and Bloom took against the idea that language evolution was an uninteresting or intractable subject. Working out the details of how language had evolved remained a monumental task, but a door had been opened. From that point on, more and more researchers felt that studying the origin and evolution of language was a legitimate academic inquiry. After a hundred years or so of uncomfortable silence, it had become intelligent, respectable, and interesting to study how humans had become a species with words. After Pinker and Bloom, more and more people stopped asking, “Did language evolve?” and wondered instead, “How did language evolve?”

Philip Lieberman

Philip Lieberman
Philip Lieberman

Chomsky often spoke of innateness. As a result, it seemed to many linguists and other cognitive scientists that the only way an innate universal grammar or language organ could exist would be if it was genetically endowed, implying that the language organ is specified somewhere in the genome. At the same time, Chomsky saw language as a perfect, formal system, so it seemed that a gene for this mathematical entity appeared out of nowhere with no precursors in other animals. This idea contributed to the widespread view that language evolution was impossible and its very existence was miraculous. While Pinker and Bloom helped to challenge this view, other researchers had resisted this idea even earlier. Among them was Philip Lieberman.

Although once a student of Chomsky’s, Lieberman had taken an opposite position to Chomsky very early on about language evolution. While Chomsky expressed no interest in it, Lieberman was examining skulls, listening to apes, and testing brains, searching for clues to the origin of language. His research is grounded in messy biology, and if you look at the problem of language evolution through his eyes it, becomes difficult to see it as either mystical or impossible but merely extremely complicated. Lieberman argues that not only should language evolution be studied, but language cannot even begin to be understood if its study does not begin with evolution.

Lieberman had completed a B.S. and M.S. in electrical engineering at MIT in 1958, but after working on several real-world projects he became bored and decided to take a linguistics course, which happened to be the first linguistics course that Noam Chomsky taught. He found the class exciting because he liked language and was intrigued by the idea of using it to understand the mind. One day while walking through the department, he heard some odd noises coming from a room off the hallway. What he heard was one of the first speech synthesizers, the DAVO, and Lieberman, the engineer studying linguistics, became interested in how speech actually works.

Human vocal tract
Human vocal tract

Once Lieberman started investigating the biophysics of speech, he became more intrigued and wrote his PhD thesis about how the physiology of breathing actually structures how we speak. Humans make all sorts of muscular maneuvers in articulating words that are carefully controlled to make sure the air pressure generated by their lungs remains at a steady level as they talk. Lieberman found that these maneuvers are keyed to the length of the sentence we intend to speak, showing that humans anticipate a long sentence before they utter a sound. The more he studied these fundamental physical constraints on human language, the more he moved away from the abstract properties of language and toward all the things that Chomsky had dismissed as epiphenomena.

A revelation that shaped his future career occurred while Lieberman was listening to a discussion on the local PBS radio station. The presenter remarked that apes couldn’t talk, and this struck him as worthy of investigation. He then traveled to New York often and spent time at Brooklyn’s Prospect Park Zoo where he taped hours and hours of ape vocalizations. Analyzing the tapes, he found that apes are unable to make the full range of human sounds because of the physiology of their tongues, which lie mostly in their mouths. The human tongue, however, extends from the larynx deep in the throat to just behind the teeth, and at points along its length it can change shape by moving up, down, forward, and back, extending, bunching up, widening and curling. When it changes shape, the whole vocal tract is altered, and each configuration produces a different sound. Lieberman also realized that although the ape cannot make as many sounds as are found in human speech, the ape had enough sounds to make a stab at talking. And in spite of the fact that they seem to have a reasonably similar vocal instrument, they just don’t use it the same way. Why this was so launched him on a search to determine the connection between motor control and the higher levels of language where Lieberman quickly came to the conclusion that a true understanding of language begins with biology.

Hired by Brown University in 1976, Lieberman began looking at the connection between language and the motor system. He started with the basal ganglia that are responsible for learning patterns of motor activity—playing tennis, dancing, or picking up a teacup. In addition, the basal ganglia control the way different physical movements and mental operations are ordered and are crucial in responding to a change in the direction of movement or thought. Lieberman worked with patients who had Parkinson’s disease where the brain progressively degenerates. The hardest-hit structures are the basal ganglia, causing tremors, rigidity, and repeated patterns of movement in patients. The patients also had difficulty comprehending syntax and tended to produce sentences that were particularly short, with only simple syntax. Lieberman thought the fact that damage to a brain area that controlled motor skills that also affected syntax was the smoking gun for a biological connection between language and motor control. Separate experiments by Steven Pinker corroborated this connection between the brain, motor skills, and syntax.

Brain structure
Basal ganglia

Lieberman went on to study the basal ganglia connection by comparing the linguistic and motor performance of Parkinson’s patients with a different group, individuals who were climbing Mount Everest. Parkinson’s is a progressive and fatal disease, whereas damage to the basal ganglia of climbers on Everest results from lack of oxygen. In most cases it is temporary in the climbers, but some of the temporary deficits in climbers are much the same as the long-term deficits in Parkinson’s patients. Lieberman set up a monitoring unit at Everest’s Base Camp, 5,300 meters above sea level. The climbers were given baseline cognitive tests and samples of their speech were taken. As the climbers proceeded up the mountain and stopped at the next four camps, further tests and speech samples were obtained by radio link.

One of the abilities that Lieberman examined was how the climbers assembled the bits that make up distinctive sounds of speech. For example, when a b is pronounced, at least two movements must be coordinated. At some point, the lips open and release air while the vocal cords vibrate deep in the throat. Timing the onset of voicing in speech sounds is still another complicated motor skill at which every normal speaker is expert, although few realize this consciously. It is also another kind of movement sequence that is affected by Parkinson’s disease. Lieberman showed that the higher the climbers went up the mountain, the more trouble they had with timing and the more their syntax degraded along with their thinking. Climbers on Everest can become inflexible in their thinking as many stories attest to about bad decisions made on the mountain. One of Lieberman’s climbers who scored well at base camp demonstrated extreme anomalies in his speech and a dramatic decline in thinking as he ascended. When told by researchers that he was not functioning normally and advised to descend, he refused. When the weather took a turn for the worse and his companions turned back, he kept going forward and a few days later fell to his death.

Lieberman believes it is clear now that the basal ganglia are crucial in regulating speech and language, which makes the motor system one of the starting points for the human ability to coordinate lips and larynx for speech and to use abstract syntax for creating meaningful and complicated expressions. Basal ganglia motor control is something we have in common with many, many animals. Millions of years ago an animal lived that had basal ganglia and a motor system, and this creature is the ancestor of many different species alive today, including humankind. Lieberman thinks the fact that a number of animals use the basal ganglia for sequencing, whether it involves grooming or words, suggests there is no innately human specialization for simple syntax. Instead of being a recent innovation in the human lineage, the foundation of syntactic ability is an adaptation of our motor system, a primitive part of our anatomy.

And so it happened that in a relatively brief amount of time in their different ways, Steven Pinker, Sue Savage-Rumbaugh, and Philip Lieberman had enough influence to change a formerly controversial or taboo subject like language evolution into one that is now a reasonable and legitimate area for investigation. Noam Chomsky himself seems to have recognized the new atmosphere of open inquiry. When questioned about the investigation of language evolution at the 2005 Morris Symposium on the Evolution of Language, he shrugged his shoulders and said that he wouldn’t have guessed it could get so far. Within a few years, students in Linguistics 101 will probably assume that asking about language evolution was always this easy and obvious.

Pages 123456 TOP