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  • Professor Paul Bloom: This class today is about

  • language. And language is,

  • to a large extent, where the action is.

  • The study of human language has been the battleground over

  • different theories of human nature.

  • So, every philosopher or psychologist or humanist or

  • neuroscientist who has ever thought about people has had to

  • make some claim about the nature of language and how it works.

  • I'm including here people like Aristotle and Plato,

  • Hume, Locke, Freud and Skinner.

  • I'm also including modern-day approaches to computational

  • theory, cognitive neuroscience, evolutionary theory and

  • cultural psychology. If you hope to make it with a

  • theory of what people are and how people work,

  • you have to explain and talk about language.

  • In fact, language is sufficiently interesting that,

  • unlike most other things I'll talk about in this class,

  • there is an entire field devoted to its study,

  • the field of linguistics that is entirely devoted to studying

  • the nuances and structures of different languages.

  • Now, I'll first, before getting into details,

  • make a definitional point. When I'm talking about language

  • I'm meaning systems like English and Dutch and Warlpiri and

  • Italian and Turkish and Urdu and what we've seen and heard right

  • now in class in the demonstration that preceded the

  • formal lecture. Now, you could use language in

  • a different sense. You could use the term

  • "language" to describe what dogs do, or what chimpanzees do,

  • or birds. You could use language to

  • describe music, talk about the--a musical

  • language or art, or any communicative system,

  • and there's actually nothing wrong with that.

  • There's no rule about how you're supposed to use the word

  • "language." But the problem is if you use

  • the word "language" impossibly, incredibly broadly,

  • then from a scientific point of view it becomes useless to ask

  • interesting questions about it. If language can refer to just

  • about everything from English to traffic signals,

  • then we're not going to be able to find interesting

  • generalizations or do good science about it.

  • So, what I want to do is, I want to discuss the

  • scientific notion of language, at first restricting myself to

  • systems like English and Dutch and American sign language and

  • Navajo and so on. Once we've made some

  • generalizations about language in this narrow sense,

  • we could then ask, and we will ask,

  • to what extent do other systems such as animal communication

  • systems relate to this narrower definition.

  • So we could ask, in this narrow sense,

  • what properties do languages have and then go on to ask,

  • in a broader sense, what other communicative

  • systems also possess those properties.

  • Well, some things are obvious about language so here are some;

  • here are the questions we will ask.

  • This will frame our discussion today.

  • We'll first go over some basic facts about language.

  • We'll talk about what languages share, we'll talk about how

  • language develops, and we'll talk about language

  • and communication in nonhumans. I began this class with a

  • demonstration of--that illustrates two very important

  • facts about language. One is that languages all share

  • some deep and intricate universals.

  • In particular, all languages,

  • at minimum, are powerful enough to convey an abstract notion

  • like this; abstract in the sense that it

  • talks about thoughts and it talks about a proposition and

  • spatial relations in objects. There's no language in the

  • world that you just cannot talk about abstract things with.

  • Every language can do this. But the demonstration also

  • illustrated another fact about language, which is how different

  • languages are. They sound different.

  • If you know one language, you don't necessarily know

  • another. It's not merely that you can't

  • understand it. It could sound strange or look

  • unusual in the case of a sign language.

  • And so, any adequate theory of language has to allow for both

  • the commonalities and the differences across languages.

  • And this is the puzzle faced by the psychology and cognitive

  • science of language. Well, let's start with an

  • interesting claim about language made by Charles Darwin.

  • So, Darwin writes, "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."

  • And what Darwin is claiming here, and it's a controversial

  • and interesting claim, is that language is special in

  • that there's some sort of propensity or capacity or

  • instinct for language unlike the other examples he gives.

  • Not everything comes natural to us but Darwin suggests that

  • language does. Well, why should we believe

  • this? Well, there are some basic

  • facts that support Darwin's claim.

  • For one thing, every normal--every human

  • society has language. In the course of traveling,

  • cultures encounter other cultures and they often

  • encounter cultures that are very different from their own.

  • But through the course of human history, nobody has ever

  • encountered another group of humans that did not have a

  • language. Does this show that it's built

  • in? Well, not necessarily.

  • It could be a cultural innovation.

  • It could be, for instance,

  • that language is such a good idea that every culture comes

  • across it and develops it. Just about every culture uses

  • some sort of utensils to eat food with, a knife and a fork,

  • chopsticks, a spoon. This probably is not because

  • use of eating utensils is human nature, but rather,

  • it's because it's just a very useful thing that cultures

  • discover over and over again. Well, we know that this

  • probably is not true with regard to language.

  • And one reason we know this is because of the demonstrated case

  • studies where a language is created within a single

  • generation. And these case studies have

  • happened over history. The standard example is people

  • involved in the slave trade. The slave trade revolving

  • around tobacco or cotton or coffee or sugar would tend to

  • mix slaves and laborers from different language backgrounds,

  • in part deliberately, so as to avoid the possibility

  • of revolt. What would happen is these

  • people who were enslaved from different cultures would develop

  • a makeshift communication system so they could talk to one

  • another. And this is called a "pidgin,"

  • p-i-d-g-i-n, a pidgin. And this pidgin was how they

  • would talk. And this pidgin was not a

  • language. It was strings of words

  • borrowed from the different languages around them and put

  • together in sort of haphazard ways.

  • The question is what happens to the children who are raised in

  • this society. And you might expect it that

  • they would come to speak a pidgin, but they don't.

  • What happens is, in the course of a single

  • generation, they develop their own language.

  • They create a language with rich syntax and morphology and

  • phonology, terms that we'll understand in a few minutes.

  • And this language that they create is called a "creole."

  • And languages that we know now as creoles, the word refers back

  • to their history. That means that they were

  • developed from pidgins. And this is interesting because

  • this suggests that to some extent the ability to use and

  • understand and learn language is part of human nature.

  • It doesn't require an extensive cultural history.

  • Rather, just about any normal child, even when not exposed to

  • a full-fledged language, can create a language.

  • And more recently, there's been case studies of

  • children who acquire sign language.

  • There's a wonderful case in Nicaragua in sign language where

  • they acquire sign language from adults who themselves are not

  • versed in sign language. They're sort of second-language

  • learners struggling along. What you might have expected

  • would be the children would then use whatever system their adults

  • use, but they don't. They "creolized" it.

  • They take this makeshift communication system developed

  • by adults and, again,

  • they turn it into a full-blown language, suggesting that to

  • some extent it's part of our human nature to create

  • languages. Also, every normal human has

  • language. Not everybody in this room can

  • ride a bicycle. Not everybody in this room can

  • play chess. But everybody possesses at

  • least one language. And everybody started to

  • possess at least one language when they were a child.

  • There are exceptions, but the exceptions come about

  • due to some sort of brain damage.

  • Any neurologically normal human will come to possess a language.

  • What else do we know? Well, the claim that language

  • is part of human nature is supported by neurological

  • studies, some of which were referred to

  • in the chapters on the brain that you read earlier that talk

  • about dedicated parts of the brain that work for language.

  • And if parts of these brains--if parts--if these parts

  • of the brain are damaged you get language deficits or aphasias