How Language Began

by Daniel L. Everett

  § David Gil, a researcher at the Max Planck Institute in Germany, has told me that in the folklore of contemporary local Indonesian communities, one hears of sightings of small, human-like creatures of the forest. It is fascinating to think either that the Hobbits might still exist or that stories about them might have entered the cultures of local Indonesian areas more than 18,000 years ago and are still told today. Less excitingly, though, it is more likely that the creature Gil has heard described is entirely fictitious, an invention of the local cultures. Its description’s similarity to small Homo erectus is probably coincidental.

  ¶ Human males have the longest penises relative to body size in the primate world. This may result from the fact that humans are the only primates to engage habitually in face-to-face copulation. This in turn may have strengthened male–female bonding. Alternatively, and for whatever reason, human females may have been more attracted to better-endowed males.

  # Glial cells and mast cells form part of the brain’s neuroimmune system, independent of the immune system that protects the rest of the body.

  6

  How the Brain Makes Language Possible

  The complexity of the nervous system is so great, its various association systems and cell masses so numerous, complex, and challenging, that understanding will forever lie beyond our most committed efforts.

  Santiago Ramón y Cajal (1909)

  HOWEVER THE HUMAN BRAIN reached its current state, Homo sapiens is now the proud owner of the greatest cognitive device in the history of earth. It is time, therefore, to ask how this device functions and how it is put together.1 In particular, how does the human brain enable human language? Part of the answer to that question is that the human brain shares an organisational characteristic with the human vocal apparatus (the parts that help to create speech, including our lungs, tongue, teeth and nasal passages). Like the vocal apparatus the brain reuses pre-existing systems and exploits them for purposes other than what they might have originally evolved for – or at least what they were used for prior to their being marshalled for language use. This is a point made in the writings of numerous neuroscientists and philosophers. Neither the brain nor the vocal apparatus evolved exclusively for language. They have, however, undergone a great deal of microevolution to better support human language. It is often claimed that there are language-specific areas of the brain such as Wernicke’s area or Broca’s area. There are not. On the other hand, in spite of the lack of dedicated language regions of the brain, several researchers have shown the importance of the subcortical region known as the basal ganglia to language. Basal ganglia are a group of brain tissues that appear to function as a unit and are associated with a variety of general functions such as voluntary motor control, procedural learning (routines or habits), eye movements and emotional function. This area is strongly connected to the cortex and thalamus, along with other brain areas. These areas are implicated in speech and throughout language. Philip Lieberman refers to the disparate parts of the brain that produce language as the Functional Language System.2

  The general nature of the basal ganglia (sometimes referred to as the ‘reptilian brain’), their role in speech and their responsibility for habit formation, teaches us several things. First, this region is a fundamental component of language function, even though not specifically evolved for language. It is known that the ganglia are crucial for language because harm to them produces a number of aphasic conditions. If these vestigial portions of the cerebellum and reptilian brain are part of the Functional Language System, however, this indicates that responsibility for language lies with various regions of the brain that contribute in multiple ways at a higher level of organisation in our mental or cortical life than merely language. This tells us that language is at least partially a series of acquired habits and routines, along with others like skiing, bicycle-riding, typing and so on, since habits and routines are the purview of the basal ganglia.

  Another reason the basal ganglia are important is that their role in language illustrates the importance of the theory of microgenetics. This theory claims that human thinking engages the entire brain, beginning with the oldest parts of the brain first. Or, as it is put in a recent study:

  The implication of microgenetic theory is that cognitive processes such as language comprehension remain integrally linked to more elementary brain functions, such as motivation and emotion … linguistic and nonlinguistic functions should be tightly integrated, particularly as they reflect common pathways of processing.3

  Many researchers underscore why one should not jump to conclusions about the significance of the fact that some kinds of knowledge are found in specific regions of the brain:

  [E]verything humans know and do is served by and represented in the human brain … Our best friend’s phone number and our spouse’s shoe size must be stored in the brain, and presumably they are stored in nonidentical ways, which could … show up someday on someone’s future brain-imaging machine … The existence of a correlation between psychological and neural facts says nothing in and of itself about innateness, domain specificity, or any other contentious division of the epistemological landscape.

  The authors add:

  Well-defined regions of the brain may become specialised for a particular function as a result of experience. In other words, learning itself may serve to set up neural systems that are localised and domain-specific, but not innate.4

  Therefore, it is very important to exercise care before speculating that any human knowledge is inborn. The brain is built for learning. It is always best to consider learning as the reason for any information found in any part of the brain, at least before claiming it is hardwired knowledge.

  It is, of course, possible that there are concepts inborn in humans. But this is a problematic idea. To implant information innately in the brain the human genotype would need to come prespecified as responsible for different concepts, actual propositional knowledge. That is, there would need to be a gene or a gene network for each purportedly innate concept, perhaps something like ‘Heights are scary’ or ‘Don’t associate with cheaters’ or ‘Nouns refer to things’ or ‘You can’t question subjects in subordinate clauses’. On the other hand it is possible that the cytoarchitecture of the brain makes some things easier to learn in different regions due to the types or configuration of cells in those regions or the connections of some regions to other regions. In fact, there is no uncontroversial evidence that brains either do or do not have specialised, hardwired networks or modules independent of learning, aside from their purely physical properties. Notwithstanding this absence of evidence, there are plenty of researchers who insist that concepts are inborn. Related to this, it is believed by some that innate, language-specialised regions of the brain exist. One of the best known of these regions is Broca’s area, a hypothesised region on the left side of the brain. (More technically, it is that part of the brain located at the pars opercularis and pars triangularis of the inferior frontal gyrus.)

  The purported specialisation of Broca’s area was first suggested in the nineteenth century. The claim emerged from the work of the French researcher and physician Pierre Paul Broca, working with a patient he nicknamed ‘Tan’ because this was the only word that the patient could utter.

  To many modern neuroscientists this is no longer as convincing as it was when first proposed by Broca.5 In fact, for most researchers, Broca’s area does not exist as a clearly demarcated part of the brain. As one author further clarifies,

  … anatomical definitions are often quite imprecise with respect to specific language functions that are processed in the cortical areas. Thus, localizing Broca’s region in the context of a functional imaging study analyzing linguistic material, or a lesion study of a Broca aphasic may refer to completely different areas with different cytoarchitecture, connectivity and, ultimately, function.6

  In spite of growing professional scepticism of Broca’s studies, many people still think of his subject Tan’s affected br
ain region as a special area for language. Ned Sahin and co-authors have claimed:

  Neighboring probes within Broca’s area revealed distinct neuronal activity for lexical (~200 milliseconds), grammatical (~320 milliseconds), and phonological (~450 milliseconds) processing, identically for nouns and verbs, in a region activated in the same patients and task in functional magnetic resonance imaging. This suggests that a linguistic processing sequence predicted on computational grounds is implemented in the brain in fine-grained spatiotemporally patterned activity.7

  The problem with this type of research methodology, however, is that Broca’s area – assuming that one could define its location in any valid way – is more general in its function than language. There are indeed some parts of the brain that are linked to language. There must be, in fact. But they are not generally dedicated exclusively to language. Focusing on language or grammar in a region of the brain such as Broca’s area is like claiming that forks exhaust the function of the kitchen.

  More precisely, though, today one would say that there are regions of the brain that participate in many cognitive tasks and that they can enter different neural networks for different tasks. For language, the region often spoken of loosely as Broca’s area is a part of the aforementioned Functional Language System, linking various multitasking parts of the brain, as needed, for language. Supporting the assertion that Broca’s area is not ‘the language region’ of the brain is the ironic fact that Broca’s area can be destroyed without affecting language if the subject is young enough. In other words, Broca’s area is not only not exclusively dedicated to language but also regularly engaged during a range of cognitive tasks, such as coordination of motor-related activities.

  As an example of other jobs performed by this purported region, consider what happens when someone is shown hand shadows of moving animals – the region near the classic Broca’s area is activated. The region is also activated if someone listens to or performs music. But these are clearly not language-specific tasks. Rather, what they indicate is that Broca’s ‘area’ has a function more general than language. It seems instead to be an ‘activity-coordination part’ of the brain. Language production is all but one activity among many. This is not to say that Broca’s area is fully understood or that it is known with certainty that there are no hereditary language-specific regions of the brain. The claim is only that such regions haven’t yet been discovered.

  Moreover, new evidence being gathered suggests that such areas may never be discovered. Research hints that brains are composed of polyvalent (doing more than one thing) networks, along the lines of the Functional Language System, that can reform or be reused for a variety of diverse functions.8 Recent findings in research at MIT argue that the ‘visual cortex’, the region of the brain usually associated with vision in sighted individuals, can be used for non-visual tasks.9

  Again, this work is extremely important for any attempt to link cognitive functions with specific regions of the brain. Such work is also important for anyone tempted to conflate statements like ‘this region of the brain does X, among other things’ vs ‘this region of the brain is genetically specified to do X and X alone’. These are separate issues entirely. To find something in the brain is not to discover that a cognitive ability is innately specified to be located exclusively in that portion of the brain.

  The MIT-led research is by no means alone in showing how impressive brain plasticity is. Genetic transcription factors responsible for the localisation or specialisation of different regions of the brain for different cognition functions do not seem to be the result of genetically determined links between different cognitive functions and cerebral topography. The lungs, larynx, teeth, tongue, nose and so on are all vital for non-signed language, just as the hands are crucial for signed languages, but none of these are either individually or collectively language organs. How bizarre it would be to claim that the hands are language organs.

  The same issues arise for any claim of neuroanatomical specialisation for language. Another such area, commonly claimed to be a language-specific area, is a region known as Wernicke’s area. This is located in the posterior section of the superior temporal gyrus in the dominant cerebral hemisphere of a given individual. That means that for right-handed people it is found in the left hemisphere. For lefties, language seems more distributed. Though it is still found in the left hemisphere, left-handers have better ability to recover from strokes that affect language due to less narrow localisation for the left-handed than for right-handed folk. At one time, this region of the posterior temporal lobe of the brain was believed to be specialised for understanding written and spoken language.*

  Unfortunately for anyone interested in marshalling anatomical support for the innateness of language, Wernicke’s area is not exclusively or even mainly dedicated to language. Wernicke’s area, just as Broca’s area, is part fiction, as there are no agreed-upon definitions of either the location or its extent. That makes it difficult even to say that there is such an area with any precision. Second, recent research shows that this region is connected to other areas of the brain that are, as was the case with Broca’s, far more general in their function than language, such as motor control, including the pre-motor organisation of potential activities – things like getting your fingers ready to play the guitar before you begin to play. Third, as the research above indicates, even if one did find an area specialised for a particular function in one or even in a million subjects, the next subject one meets could in many cases be using that area of their brain differently, depending on their individual developmental history. The lesson to take away from this is that parts of the brain develop in each individual as a home-base for multiple, though related, tasks.

  But if the organisation of the human brain is that plastic, how is it that the sapiens brain takes the form and shape that it does? The answer is that brain growth and development is guided not only by genes but also by histones that control ‘transcription factors’. A transcription factor is simply a protein that connects (‘binds’) to specific sequences of DNA. By doing this, these factors are able to determine the rate of transcription. That is how information from the genes is passed from DNA to messenger RNA. These transcription factors are crucial for development. They regulate how genes are manifested or ‘expressed’. Transcription factors play a role in the development of all organisms. The larger the size of the genome, the larger the number of transcription factors necessary to regulate the expression of the larger number of genes. Not only that, but organisms with larger genomes tend to have even more transcription factors per gene.

  It is also known now that brain specialisation and anatomy can be influenced by culture. This makes it much harder to tease apart evidence for ‘pure’ biology from biological properties influenced or supplanted by learning or the environment. Psychologists have shown that reading-challenged children who had experienced as little as six months of intensive remedial reading instruction grew new white-matter connections in their brains. And this study is but one of many that have found that culture can change the structure and functionality of the brain. Other studies have shown that the connections between portions of the brain can weaken or strengthen over time, based on the cultural experiences of the individual.

  Because culture can change the form of the brain, and since there is no knowledge of any cognitive function that is innate to a specific location in all brains, the difficulty of using arguments from cerebral organisation or anatomy for the idea that language is innate is clear. And it is equally implausible to claim that specific regions of the brain are genetically specialised for specific tasks. The brain uses and reuses its various areas in order to accomplish all of the challenges that modern humans confront. Evolution has prepared humans to think more freely than any other creature by giving them a brain capable of learning culturally rather than one that relies on cognitive instincts. From one vantage point, localisation in the brain is trivial. Everything we know is somewhere in our bra
in. Therefore, finding that this or that kind of knowledge is located in a specific part of the brain is not evidence for innate knowledge. I was born in Southern California. That doesn’t mean I was predestined to be there. Everyone has to be born somewhere.

  Occasionally one reads linguistics research claiming that language is housed in the brain and underwritten by specific genes in the same way that vision, growing arms, hearing and our other natural abilities seem to be. But language is not like vision. Vision is a biological system. Language is perhaps a bit like the use of vision in perception, in that it requires culture for interpretation and use (as in art and literature). But we now know that language is a nexus of social, computational, psychological and cultural constraints and requirements. With experience, as we age and learn, parts of the brain come to specialise for and house components of language. But this is true for everything we know. I know how to boil water. That is somewhere in my brain. But neither boiling water nor language is innate simply because it is found in a specific part of the brain – not even if such things are found in roughly the same part of all brains across all individuals.

  It is also often claimed by Rutgers philosopher Jerry Fodor and others that language is an encapsulated mental module (meaning that it operates independently from the rest of the brain). But Evelina Fedorenko, an MIT neuroscientist, has shown that when we use language, we always draw on both specific and general knowledge.10 First, an individual might access a particular word meaning stored in his or her brain, but they will subsequently also access the general cultural knowledge they possess in order to interpret that word in their present circumstances. Therefore, language is not encapsulated, nor is it an autonomous ability. And it does not have a genetically dedicated home in the brain. But innate location and autonomy are often appealed to in order to claim that language itself is innate, an encapsulated module.