Placeholder Image

字幕表 動画を再生する

  • My name is Steve Pinker, and I’m Professor of Psychology at Harvard University.  And

  • today I’m going to speak to you about language.  I’m actually not a linguist, but a

  • cognitive scientist.  I’m not so much interested as language as an object in its own right,

  • but as a window to the human mind. Language is one of the fundamental topics

  • in the human sciences.  It’s the trait that most conspicuously distinguishes humans

  • from other species, it’s essential to human cooperation; we accomplish amazing things

  • by sharing our knowledge or coordinating our actions by means of words.  It poses profound

  • scientific mysteries such as, how did language evolve in this particular species?  How does

  • the brain compute language? But also, language has many practical applications not surprisingly

  • given how central it is to human life.  Language comes so naturally to us that were

  • apt to forget what a strange and miraculous gift it is.  But think about what youre

  • doing for the next hour.   Youre going to be listening patiently as a guy makes noise

  • as he exhales.  Now, why would you do something like that?  It’s not that I can claim that

  • the sounds I’m going to make are particularly mellifluous, but rather I’ve coded information

  • into the exact sequences of hisses and hums and squeaks and pops that I’ll be making.

  •  You have the ability to recover the information from that stream of noises allowing us to

  • share ideas. Now, the ideas we are going to share are about

  • this talent, language, but with a slightly different sequence of hisses and squeaks,

  • I could cause you to be thinking thoughts about a vast array of topics, anything from

  • the latest developments in your favorite reality show to theories of the origin of the universe.

  •  This is what I think of as the miracle of language, its vast expressive power, and it’s

  • a phenomenon that still fills me with wonder, even after having studied language for 35

  • years.  And it is the prime phenomenon that the science of language aims to explain.  

  • Not surprisingly, language is central to human life.  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:  grammar, the assembly of words, phrases and sentences; phonology, the

  • study of sound; semantics, the study of meaning; and pragmatics, the study of the use of language

  • in conversation.  Scientists interested in language also

  • study how it is processed in real time, a field called psycholinguistics; how is it

  • acquired by children, the study of language acquisition.  And how it is computed in the

  • brain, the discipline called neurolinguistics. 


  • Now, before we begin, 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.  And as Darwin pointed out, children have no instinctive tendency to write,

  • but have to learn it through construction and schooling.

  • 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.  Take one of the most famous of these rules, the rule not to

  • split infinitives.   According to this rule, Captain Kirk made

  • a grievous grammatical error when he said that the mission of the Enterprise wasto

  • boldly go where no man has gone before.”  He should have said, according to these

  • editors, “to go boldly where no man has gone before,” which immediately clashes

  • with the rhythm and structure of ordinary English.  In fact, this prescriptive rule

  • was based on a clumsy analogy with Latin where you can’t splint an infinitive because it’s

  • a single word, as in facary[ph] to do.  Julius Caesar couldn’t have split an infinitive

  • if he wanted to.  That rule was translated literally over into English where it really

  • should not apply.   Another famous prescriptive rule is that,

  • one should never use a so-called double negative.  Mick Jagger should not have sung, “I can’t

  • get no satisfaction,” he really should have sung, “I can’t get any satisfaction.”

  •  Now, this is often promoted as a rule of logical speaking, butcan’t” andany

  • is just as much of a double negative ascan’t” andno.”  The only reason thatcan’t

  • get any satisfactionis deemed correct andcan’t get no satisfactionis deemed

  • ungrammatical is that the dialect of English spoken in the south of England in the 17th

  • century usedcan’t” “anyrather thancan’t” “no.”  

  • If the capital of England had been in the north of the country instead of the south

  • of the country, thencan’t get no,” would have been correct andcan’t get

  • any,” would have been deemed incorrect. 

  • There’s nothing special about a language that happens to be chosen as the standard

  • for a given country.  In fact, if you compare the rules of languages and so-called dialects,

  • each one is complex in different ways.  Take for example, African-American vernacular English,

  • also called Black English or Ebonics.  There is a construction in African-American where

  • you can say, “He be workin,” which is not an error or bastardization or a corruption

  • of Standard English, but in fact conveys a subtle distinction, one that’s different

  • than simply, “He workin.”  “He be workin,” means that he is employed; he has a job, “He

  • workin,” means that he happens to be working at the moment that you and I are speaking.

  •   Now, this is a tense difference that can be

  • made in African-American English that is not made in Standard English, one of many examples

  • in which the dialects have their own set of rules that is just as sophisticated and complex

  • as the one in the standard language.   Now, 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.) Babies (and other mammals) communicate without speech

  • For example, we know from ingenious experiments that non-linguistic creatures, such as babies

  • before theyve 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--visual

  • thinking We also know that even in creatures that do

  • have language, namely adults, a lot of thinking goes on in forms other than language, for

  • example, visual imagery.  If you look at the top two three-dimensional figures in this

  • display, and I would ask you, do they have the same shape or a different shape?  People

  • don’t solve that problem by describing those strings of cubes in words, but rather by taking

  • an image of one and mentally rotating it into the orientation of the other, a form of non-linguistic

  • thinking.   (3.) We use tacit knowledge to understand

  • language and remember the gist For that matter, even when you understand

  • language, what you come away with is not in itself the actual language that you hear.

  •  Another important finding in cognitive psychology is that long-term memory for verbal material

  • records the gist or the meaning or the content of the words rather than the exact form of

  • the words.   For example, I like to think that you retain

  • some memory of what I have been saying for the last 10 minutes.  But I suspect that

  • if I were to ask you to reproduce any sentence that I have uttered, you would be incapable

  • of doing so.  What sticks in memory is far more abstract than the actual sentences, something

  • that we can call meaning or content or semantics.  

  • In fact, when it even comes to   understanding a sentence, the actual words are the tip of

  • a vast iceberg of a very rapid, unconscious, non-linguistic processing that’s necessary

  • even to make sense of the language itself.  And I’ll illustrate this with a classic

  • bit of poetry, the lines from the shampoo bottle.  “Wet hair, lather, rinse, repeat.”

  •   Now, in understanding that very simple snatch

  • of language, you have to know, for example, that when you repeat, you don’t wet your

  • hair a second time because its already wet, and when you get to the end of it and you

  • seerepeat,” you don’t keep repeating over and over in infinite loop, repeat here

  • means, “repeat just once.”  Now this tacit knowledge of what the writers **** of

  • language had in mind is necessary to understand language, but it, itself, is not language.

  •  (4.) If language is thinking, then where did

  • it come from? Finally, if language were really thought,

  • it would raise the question of where language would come from if it were incapable of thinking

  • without language.  After all, the English language was not designed by some committee

  • of Martians who came down to Earth and gave it to us.  Rather, language is a grassroots

  • phenomenon.  It’s the original wiki, which aggregates the contributions of hundreds of

  • thousands of people who invent jargon and slang and new constructions, some of them

  • get accumulated into the language as people seek out new ways of expressing their thoughts,

  • and that’s how we get a language in the first place.  

  • 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

  • (note correct spelling, named after the two linguists who first formulated it, namely

  • that language can affect thought.  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.  

  • Now that we have set aside what language is not, 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.   There are the 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.  There are rules, 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 assemble words into phrases and sentences; Morphology, the

  • rules that allow us to assemble bits of words, like prefixes and suffixes into complex words;

  • Phonology, the rules that allow us to combine vowels and consonants into the smallest words.

  •  And then all of this knowledge of language has to connect to the world through interfaces

  • that allow us to understand language coming from others to produce language that others

  • can understand us, the language interfaces.

  • Let’s start with words. 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,

  • duckdoesn’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

  • and an entry in the mental lexicon might look something like this.  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.   Now, one of the remarkable facts about the

  • mental lexicon is how capacious it is.  Using dictionary sampling techniques where you say,

  • take the top left-hand word on every 20th page of the dictionary, give it to people

  • in a multiple choice test, correct for guessing, and multiply by the size of the dictionary,

  • 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, youre reminded about the remarkable capacity of

  • human long-term memory to store the meanings and sounds of words.  

  • But of course, we don’t just blurt out individual words, we combine them into phrases and sentences.

  •  And that brings up the second major component of language; namely, grammar.  

  • Now the modern study of grammar is inseparable to the contributions of one linguist, the

  • famous scholar, Noam Chomsky, who set the agenda for the field of linguistics for the

  • last 60 years.  To begin with, 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.  

  • Except for a small number of clichéd formulas, just about any sentence that you produce or

  • understand is a brand new combination produced for the first time perhaps in your life, perhaps

  • even in the history of the species.  We have to explain how people are capable of doing

  • it.  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.  For that reason, Chomsky has insisted that linguistics

  • is really properly a branch of psychology and is a window into the human mind. 

  • A second insight is that languages have a syntax which can’t be identified with their

  • meaning.  Now, the only quotation that I know of, of a linguist that has actually made

  • it into Bartlett’s Familiar Quotations, is 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 very close to 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

  • as a word salad.   A third insight is that syntax doesn’t consist

  • of a string of word by word associations as in stimulus response theories in psychology

  • where producing a word is a response which you then hear and it becomes a stimulus to

  • producing the next word, and so on.  Again, the sentence, “colorless green ideas sleep

  • furiously,” can help make this point.  Because if you look at the word by word transition

  • probabilities in that sentence, for example, colorless and then green; how often have you

  • heard colorless and green in succession.  Probably zero times.  Green and ideas, those two words

  • never occur together, ideas and sleep, sleep and furiously.  Every one of the transition

  • probabilities is very close to zero, nonetheless, the sentence as a whole can be perceived as

  • a well-formed English sentence.   Language in general has long distance dependencies.

  •  The word in one position in a sentence can dictate the choice of the word several positions

  • downstream.  For example, if you begin a sentence witheither,” somewhere down

  • the line, there has to be anor.”  If you have anif,” generally, you expect

  • somewhere down the line there to be a “then.”  There’s a story about a child who says

  • to his father, “Daddy, why did you bring that book that I don’t want to be read to

  • out of, up for?”  Where you have a set of nested or embedded long distance dependencies.

  •   Indeed, one of the applications of linguistics

  • to the study of good prose style is that sentences can be rendered difficult to understand if

  • they have too many long distance dependencies because that could put a strain on the short-term

  • memory of the reader or listener while trying to understand them.  

  • 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.”   

  • Now, why do linguists insist that language must be composed out of  phrase structural

  • rules?   (1.) Rules allow for open-ended creativity

  • Well for one thing, that helps explain the main phenomenon that we want to explain,