The Language Instinct

Posted by Ali Reda | Posted in | Posted on 12/20/2014

Steven Pinker isn't so much interested as language as an object in its own right, but as a window to the human mind. The Biblical story of the Tower of Babel reminds us that humans accomplish great things because they can exchange information about their knowledge and intentions via the medium of language.  Language, moreover, is not a peculiarity of one culture, but it has been found in every society ever studied by anthropologists. There’s some 6,000 languages spoken on Earth, all of them complex, and no one has ever discovered a human society that lacks complex language.  For this and other reasons, Charles Darwin wrote, “Man has an instinctive tendency to speak as we see in the babble of our young children while no child has an instinctive tendency to bake, brew or write.” Language is an intricate talent and it’s not surprising that the science of language should be a complex discipline. It includes the study of how language itself works including:
  1. grammar, the assembly of words, phrases and sentences; 
  2. phonology, the study of sound; 
  3. semantics, the study of meaning; 
  4. pragmatics, the study of the use of language in conversation. For example, if I were to say, “If you could pass the guacamole, that would be awesome.” You understand that as a polite request meaning, give me the guacamole.  You don’t interpret it literally as a rumination about a hypothetical affair, you just assume that the person wanted something and was using that string of words to convey the request politely. Often comedies will use the absence of pragmatics in robots as a source of humor.  As in the old “Get Smart” situation comedy, which had a robot named, Hymie, and a recurring joke in the series would be that Maxwell Smart would say to Hymie, “Hymie, can you give me a hand?”  And then Hymie would go, {sound}, remove his hand and pass it over to Maxwell Smart not understanding that “give me a hand,” in context means, help me rather than literally transfer the hand over to me.  Or take the following example of Pragmatics in action.  Consider the following dialogue, Martha says, “I’m leaving you.”  John says, “Who is he?”  Now, understanding language requires finding the antecedents pronouns, in this case who the “he” refers to, and any competent English speaker knows exactly who the “he” is, presumably John’s romantic rival even though it was never stated explicitly in any part of the dialogue.  This shows how we bring to bear on language understanding a vast store of knowledge about human behavior, human interactions, human relationships.  And we often have to use that background knowledge even to solve mechanical problems like, who does a pronoun like “he” refer to. It’s that knowledge that’s extraordinarily difficult, to say the least to program into a computer.  
  5. Scientists interested in language also study how it is processed in real time, a field called psycholinguistics; 
  6. How is it acquired by children, the study of language acquisition.  
  7. How it is computed in the brain, the discipline called neurolinguistics. 

It’s important to not to confuse language with three other things that are closely related to language.  One of them is written language.  Unlike spoken language, which is found in all human cultures throughout history, writing was invented a very small number of times in human history, about 5,000 years ago.  And alphabetic writing where each mark on the page stands for a vowel or a consonant, appears to have been invented only once in all of human history by the Canaanites about 3,700 years ago. A second thing not to confuse language with is proper grammar.  Linguists distinguish between descriptive grammar - the rules, that characterize how people to speak - and prescriptive grammar - rules that characterize how people ought to speak if they are writing careful written prose. A dirty secret from linguistics is that not only are these not the same kinds of rules, but many of the prescriptive rules of language make no sense whatsoever. A third thing, not to confuse language with is thought.  Many people report that they think in language, but commune of psychologists have shown that there are many kinds of thought that don’t actually take place in the form of sentences.  
  1. We know from ingenious experiments that non-linguistic creatures, such as babies before they’ve learned to speak, or other kinds of animals, have sophisticated kinds of cognition, they register cause and effect and objects and the intentions of other people, all without the benefit of speech.   
  2. Types of thinking go on without language like visual thinking, When we think in visual images.
Now, this not to deny that language can affect thought and linguistics has long been interested in what has sometimes been called, the linguistic relativity hypothesis or the Sapir-Whorf Hypothesis. There’s a lot of controversy over the status of the linguistic relativity hypothesis, but no one believes that language is the same thing as thought and that all of our mental life consists of reciting sentences.  
Let’s turn to what language is beginning with the question of how language works. In a nutshell, you can divide language into three topics:
  1. Words that are the basic components of sentences that are stored in a part of long-term memory that we can call the mental lexicon or the mental dictionary. The basic principle of a word was identified by the Swiss linguist, Ferdinand de Saussure, more than 100 years ago when he called attention to the arbitrariness of the sign.  Take for example the word, “duck.”  The word, “duck” doesn’t look like a duck or walk like a duck or quack like a duck, but I can use it to get you to think the thought of a duck because all of us at some point in our lives have memorized that brute force association between that sound and that meaning,which means that it has to be stored in memory in some format, in a very simplified form. There is a symbol for the word itself, there is some kind of specification of its sound and there’s some kind of specification of its meaning. You can estimate that a typical high school graduate has a vocabulary of around 60,000 words, which works out to a rate of learning of about one new word every two hours starting from the age of one.  When you think that every one of these words is arbitrary as a telephone number of a date in history, you’re reminded about the remarkable capacity of human long-term memory to store the meanings and sounds of words.
  2. Rules or grammer, the recipes or algorithms that we use to assemble bits of language into more complex stretches of language including syntax, the rules that allow us to combine words into phrases and sentences, morphology, the rules that allow us to assemble bits of words, like prefixes and suffixes into complex words and phonology, the rules that allow us to combine vowels and consonants into the smallest words. Chomsky noted that the main puzzle that we have to explain in understanding language is creativity or as linguists often call it productivity, the ability to produce and understand new sentences. It shows that when we know a language, we haven’t just memorized a very long list of sentences, but rather have internalized a grammar or algorithm or recipe for combining elements into brand new assemblies. Rather than a set of word by word associations, sentences are assembled in a hierarchical structure that looks like an upside down tree.  Let me give you an example of how that works in the case of English.  One of the basic rules of English is that a sentence consists of a noun phrase, the subject, followed by a verb phrase, the predicate. A second rule in turn expands the verb phrase.  A very phrase consists of a verb followed by a noun phrase, the object, followed by a sentence, the complement as, “I told him that it was sunny outside.” So the number of different thoughts that we can express through the combinatorial power of grammar is not just humongous, but in a technical sense, it’s infinite. A second insight is that languages have a syntax which can’t be identified with their meaning.  The following sentence from Chomsky, from 1956, “Colorless, green ideas sleep furiously.”  Well, what’s the point of that sentence? The point is that it is meaningless.  On the other hand, any English speaker can instantly recognize that it conforms to the patterns of English syntax. Compare, for example, “furiously sleep ideas dream colorless,” which is also meaningless, but we perceive it as wrong English. Take for example, the following wonderfully ambiguous sentence that appeared in TV Guide.  “On tonight’s program, Conan will discuss sex with Dr. Ruth.”  Now this has a perfectly innocent meaning in which the verb, “discuss” involves two things, namely the topic of discussion, “sex” and the person with who it’s being discussed, in this case, with Dr. Ruth.  But is has a somewhat naughtier meaning if you rearrange the words into phrases according to a different structure in which case “sex with Dr. Ruth” is the topic of conversation, and that’s what’s being discussed.Now, phrase structure not only can account for our ability to produce so many sentences, but it’s also necessary for us to understand what they mean.  The geometry of branches in a phrase structure is essential to figuring out who did what to whom. Another important contribution of Chomsky to the science of language is the focus on language acquisition by children. Now, children can’t memorize sentences because knowledge of language isn’t just one long list of memorized sentences, but somehow they must distill out or abstract out the rules that goes into assembling sentences based on what they hear coming out of their parent’s mouths when they were little.  And the talent of using rules to produce combinations is in evidence from the moment that kids begin to speak. Children create sentences unheard from adults. At the two-word stage, which you typically see in children who are 18 months or a bit older, kids are producing the smallest sentences that deserve to be counted as sentences, namely two words long.  But already it’s clear that they are putting them together using rules in their own mind.  To take an example, a child might say, “more outside,” meaning, take them outside or let them stay outside.  Now, adults don’t say, “more outside.” So it’s not a phrase that the child simply memorized by rote, but it shows that already children are using these rules to put together new combinations. Another example, a child having jam washed from his fingers said to his mother 'all gone sticky'. Again, not a phrase that you could ever have copied from a parent, but one that shows the child producing new combinations. And famously, Chomsky claimed that children solved the problem of language acquisition by having the general design of language already wired into them in the form of a universal grammar. A spec sheet for what the rules of any language have to look like. What is the evidence that children are born with a universal grammar?  Through a more abstract argument called, “The poverty of the input.”  Namely, if you look at what goes into the ears of a child and look at the talent they end up with as adults, there is a big chasm between them that can only be filled in by assuming that the child has a lot of knowledge of the way that language works already built in. Here’s how the argument works.  One of the things that children have to learn when they learn English is how to form a question.  Now, children will get evidence from parent’s speech to how the question rule works, such as sentences like, “The man is here,” and the corresponding question, “Is the man here?”   Now, logically speaking, a child getting that kind of input could posit two different kinds of rules. There’s a simple word by word linear rule.  In this case, find the first “is” in the sentence and move it to the front.  “The man is here,” “Is the man here?” Now there’s a more complex rule that the child could posit called a structure dependent rule, one that looks at the geometry of the phrase structure tree.  In this case, the rule would be:  find the first “is” after the subject noun phrase and move that to the front of the sentence.  A diagram of what that rule would look like is as follows:  you look for the “is” that occurs after the subject noun phrase and that’s what gets moved to the front of the sentence.  Now, what’s the difference between the simple word-by-word rule and the more complex structured dependent rule?  Well, you can see the difference when it comes to performing the question from a slightly more complex sentence like, “The man who is tall is in the room.”   But how is the child supposed to learn that? How did all of us end up with the correct structured dependent of the rule rather than the far simpler word-by-word version of the rule? “Well,” Chomsky argues, “if you were actually to look at the kind of language that all of us hear, it’s actually quite rare to hear a sentence like, “Is the man who is tall in the room?  The kind of input that would logically inform you that the word-by-word rule is wrong and the structure dependent rule is right.  Nonetheless, we all grow up into adults who unconsciously use the structure dependent rule rather than the word-by-word rule.  Moreover, children don’t make errors like, “is the man who tall is in the room,” as soon as they begin to form complex questions, they use the structure dependent rule.  And that,” Chomsky argues, “is evidence that structure dependent rules are part of the definition of universal grammar that children are born with.” Let's talk about phonolgy now, To give you an example, the sequence, bluk, is not an English word, but you get a sense that it could be an English word that someone could coin a new form… that someone could coin a new term of English that we pronounce “bluk.”  But when you hear the sound khhh, you instantly know that not only isn’t it an English word, but it really couldn’t be an English word. The reason that we recognize that it’s not English is because it has sounds like khhh and sequences like khhh, which aren’t part of the formation rules of English phonology.  But together with the rules that define the basic words of a language, there are also phonological rules that make adjustments to the sounds, depending on what the other words the word appears with.  Very few of us realize, for example, in English, that the past tense suffix “ed” is actually pronounced in three different ways.  When we say, “He walked,” we pronounce the “ed” like a “ta,” walked.  When we say “jogged,” we pronounce it as a “d,” jogged.  And when we say “patted,” we stick in a vowel, pat-ted, showing that the same suffix, “ed” can be readjusted in its pronunciation according to the rules of English phonology. Now, when someone acquires English as a foreign language or acquires a foreign language in general, they carry over the rules of phonology of their first language and apply it to their second language.  We have a word for it; we call it an “accent.”  When a language user deliberately manipulates the rules of phonology, that is, when they don’t just speak in order to convey content, they pay attention as to what phonological structures are being used; we call it poetry and rhetoric.
  3. Interfaces that allow all of this knowledge of language has to connect to the world and that allow us to understand language coming from others to produce language that others can understand us. Each of us has at the top of our windpipe or trachea, a complex structure called the larynx or voice box; it’s behind your Adam’s Apple.  And the air coming out of your lungs have to go passed two cartilaginous flaps that vibrate and produce a rich, buzzy sound source, full of harmonics. Before that vibrating sound gets out to the world, it has to pass through a gauntlet or chambers of the vocal tract.  The throat behind the tongue, the cavity above the tongue, the cavity formed by the lips, and when you block off airflow through the mouth, it can come out through the nose.   Now, each one of those cavities has a shape that, thanks to the laws of physics, will amplify some of the harmonics in that buzzy sound source and suppress others.  We can change the shape of those cavities when we move our tongue around.  When we move our tongue forward and backward, for example, as in “eh,” “aa,” “eh,” “aa,” we change the shape of the cavity behind the tongue, change the frequencies that are amplified or suppressed and the listener hears them as two different vowels.   Likewise, when we raise or lower the tongue, we change the shape of the resonant cavity above the tongue as in say, “eh,” “ah,”“eh,” “ah.”  Once again, the change in the mixture of harmonics is perceived as a change in the nature of the vowel.   When we stop the flow of air and then release it as in, “t,” “ca,” “ba.”  Then we hear a consonant rather than a vowel or even when we restrict the flow of air as in “f,” “ss” producing a chaotic noisy sound.  Each one of those sounds that gets sculpted by different articulators is perceived by the brain as a qualitatively different vowel or consonant. Now, an interesting peculiarity of the human vocal track is that it obviously co-ops structures that evolved for different purposes for breathing and for swallowing and so on.  And it’s an… And it’s an interesting fact first noted by Darwin that the larynx over the course of evolution has descended in the throat so that every particle of food going from the mouth through the esophagus to the stomach has to pass over the opening into the larynx with some probability of being inhaled leading to the danger of death by choking.  And in fact, until the invention of the Heimlich Maneuver, several thousand people every year died of choking because of this maladaptive of the human vocal tract. Why did we evolve a mouth and throat that leaves us vulnerable to choking?  Well, a plausible hypothesis is that it’s a compromise that was made in the course of evolution to allow us to speak.  By giving range to a variety of possibilities for alternating the resonant cavities, for moving the tongue back and forth and up and down, we expanded the range of speech sounds we could make, improve the efficiency of language, but suffered the compromise of an increased risk of choking showing that language presumably had some survival advantage that compensated for the disadvantage in choking.  What about the flow of information in the other direction, that is from the world into the brain, the process of speech comprehension? The reason that speech recognition is such a difficult problem is because of the absence of segmentation.  Now we have an illusion when we listen to speech that consists of a sequence to sounds corresponding to words. But if you actually were to look at the wave form of a sentence on a oscilloscope, there would not be little silences between the words the way there are little bits of white space in printed words on a page, but rather a continuous ribbon in which the end of one word leads right to the beginning of the next. It’s something that we’re aware of… It’s something that we’re aware of when we listen to speech in a foreign language when we have no idea where one word ends and the other one begins.  In our own language, we detect the word boundaries simply because in our mental lexicon, we have stretches of sound that correspond to one word that tell us where it ends.  But you can’t get that information from the wave form itself. We are generally unaware of how unambiguous language is.  In context, we effortlessly and unconsciously derive the intended meaning of a sentence, but a poor computer not equipped with all of our common sense and human abilities and just going by the words and the rules is often flabbergasted by all the different possibilities.  Take a sentence as simple as “Mary had a little lamb,” you might think that that’s a perfectly simple unambiguous sentence.  But now imagine that it was continued with “with mint sauce.”  You realize that “have” is actually a highly ambiguous word. As a result, the computer translations can often deliver comically incorrect results.  

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