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

where you might lose the ability to understand or create

language. More speculatively,

there has been some fairly recent work studying the genetic

basis of language, looking at the genes that are

directly responsible for the capacity to learn and use

language. And one bit of evidence that

these genes are implicated is that some unfortunate people

have point mutations in these genes.

And such people are unable to learn and use language.

So, in general, there is some support,

at least at a very broad level, for the claim that language is

in some sense part of human nature.

Well, what do we mean by language?

What are we talking about when we talk about language?

We don't want to restrict ourselves, for instance,

to English or French. What do all languages share?

Well, all languages are creative and this means a couple

of things. One meaning is the meaning

emphasized by Rene Descartes. When Rene Descartes argued that

we are more than merely machines, his best piece of

evidence for him was the human capacity for language.

No machine could do this because our capacity for

language is unbounded and free. We could say anything we choose

to say. We have free will.

And in fact, language allows us to produce a

virtual infinity of sentences. So, we could create and

understand sentences that we never heard before.

And there are a lot of sentences.

So, if you want to estimate how many grammatical sentences under

twenty words in English, the answer is,

"a lot." And what this means is that any

theory of language use and language comprehension cannot

simply appeal to a list. When you understand a sentence

I said you have to have the capacity to understand a

sentence even if you've never heard it before.

And this is because we could effortlessly produce and

understand sentences that no human has ever said before on

earth. Would anybody volunteer to say

a sentence, non obscene, non derogatory,

that has never been spoken before on earth,

ever?

Here. I'll start.

"It's surprisingly easy to get a purple tie on eBay if you

don't care much about quality." I could imagine no one else in

the world has said this before. "I am upset that one cannot

easily download 'Buffy the Vampire Slayer' through iTunes."

Now, it's possible somebody said both these sentences

before, but you probably have not heard them.

But you understand them immediately.

So, how do you do it? Well, you have rules in your

head. You've learnt what the words

mean, but you have abstract and unconscious rules that take

these words, figure out the order,

and in a fraction of a second, give rise to understanding.

And that's the sort of thing linguists study.

So, take some standard examples from the linguistic study of

English. And bear in mind the rules

we're talking about here are not rules you explicitly know.

They're automatic rules of the same sort we're going to talk

about in the context of visual perception in that they're

implicit and unconscious and not accessible to explicit

understanding. So for instance,

immediately you read "The pig is eager to eat" versus "The pig