It is probably the most amazing thing you do
and it defines you as being human.
And you do it with ease, so much so you barely notice you're doing it.
Apple! Yeah, apple!
THEY SPEAK IN NATIVE TONGUE
Your ability to talk.
Or more precisely, the way you use language.
THEY SPEAK IN NATIVE TONGUE
Language.
COMPUTERISED VOICE: Hi, baby!
From the moment we're born, we have language in our lives.
Hi, baby!
A unique ability that defines us as human.
I can walk up to someone I don't know
and I can make a sequence of noises that I've never made before
by pushing air through my mouth.
I will take a thought in my head and make it go into their head,
and that's an incredible trick.
Other animals may use sounds to communicate
but we're the only ones on the planet who can talk.
Speech and language distinguishes us from all other species.
We are not only using words to be able to express ourselves
but we are really expressing our thought processes
that are unique to ourselves.
For most of us it just happens.
It's such a sophisticated skill
and yet children learn it so easily with minimal effort at all.
That's Mummy.
And when you start thinking about it,
it is quite miraculous how the brain does it.
But despite decades of research, how we learn to talk remains a mystery.
How did this ability evolve?
Why is it uniquely human?
And is it something we are born with or something that we learn?
It strikes me it's surprising and odd
that we know an enormous amount about, for example,
the first fractions of a second in the history of the universe,
but we really know very little at all about what makes us human
and where language comes from.
BABY BABBLES
Daddy.
The wonder of language may not yet be fully understood.
BABY BABBLES
But how we start to talk is now being observed
minute by minute for the first time.
Cognitive scientist Deb Roy realised
that to discover how a child learns to speak...
He'd have to be able to see and hear them 24 hours a day.
His solution was to take the extraordinary step
of turning his own home into a language laboratory,
and his guinea pig was his own son.
My wife and I were expecting our first child
and we had many conversations around, you know, would this be possible,
could we set up our home as an observation space
and actually capture this kind of rich longitudinal record
of our own child's development from birth?
And that's what we set out to do.
And so was born the Speech Home Project,
The most ambitious language observation experiment ever seen.
Cameras and microphones recorded every second of Deb's son's life
from the moment he was born until he was three-years-old.
Capturing in precise detail the process of how we learn to talk.
Baa!
Ball.
Blue ball. Blue ball.
Blue ball, yeah.
From the earliest unintelligible babble
to the emergence of a very first word.
Apple. Apple.
Yeah, apple.
My interest going in was really to understand
the earliest stages of language formation,
and the typical development stages in language,
a child will go from babbling to using single words
usually as a complete request and descriptions,
and then from that they will start what's called the two-word stage
where they'll put two words together like "more milk"
and from that, very quickly more complex grammatical structures emerge.
My focus and my aim was to capture the phase
up to the two-word utterance
and that could happen anywhere between second and third birthday.
It turned out my son was an early talker
so by the time his second birthday arrived
we had the main data set we wanted.
By the time recording was complete,
more than 240,000 hours of information
and 16 million words had been collected.
It's a lot of data but in its raw form it's useless
and so the challenges this now sets up for us
is how do you start extracting the right kind of metadata,
transcripts of who said what,
annotations of where those people were,
annotations of how they're moving
and the relationships that they were in as they were speaking.
And these are the, the tools that we are now building
to analyse the raw data,
and from that, we're starting to see some,
some early insights into the patterns of language development.
Despite the mountains of video footage,
Deb Roy is already uncovering the intricate effect
daily life has on language development.
It seems cooing to your baby is not just instinct, it's essential.
In the months leading up to their son's first words,
he and his wife unconsciously simplified their speech.
Then as their son's own speech develops,
they began to use longer sentences again,
mirroring the child's own development.
What's that over there? Over there, that ball?
Green ball. Oh!
For the very first time, the analysis has also enabled
Deb to piece together the precise emergence of individual words,
charting how a new word is born.
OK, water, water.
Gaga, gaga.
So my son, around his first birthday,
started using the sound "gaga" to indicate water,
and then over the next several months
learned to slowly approximate the proper speech form.
Water.
Just like time lapse video lets you capture a flower blossoming,
what we're going to hear is the blossoming of a speech form.
OK, water?
Water.
Water? Water?
Water.
That's water.
It will take years for Deb Roy and his team to analyse all of the data
but buried within this footage
are the secrets of how we learn language.
If the patterns can be unlocked,
then once this remarkable project is complete
we will have the clearest understanding yet
of how a child achieves the remarkable feat of learning to talk.
By the time a child is five, they'll know as many as 5,000 words.
THEY SPEAKS IN NATIVE TONGUE
My voice changes when I get in a situation.
That requires a rather precise placement of the tip of the tongue.
At the third stroke the time will be five...
Language is exclusively human
and it's something that comes naturally to us.
From their voice, so it's clear the voice is deeply expressive.
Despite decades of intense investigation,
we still know very little about the basic origins of language.
ELEPHANT ROARS
Sunlight.
While other creatures can communicate
their basic needs and emotions to each other,
we're the only species that can convey complex meaning and thought.
T or the D at the end of a word for, say, dot or dog.
It's remarkable that no other animal has ever developed speech.
What is it that makes us unique?
Do this, Vicky.
HE BLOWS RASPBERRY
Another sound resembles the letter K.
Vicky, sit up.
Not even our closest relatives, the chimps, can talk.
Psychologists spent nearly seven years
trying to teach Vicky to speak with little success.
Resembles the letter T.
And in this case they really tried to teach a chimp to say some basic words
and completely failed, and everyone knew of course that,
say, parrots can learn to imitate speech.
So it was kind of a very surprising and eye-opening experience
to see that these chimps with great big brains for an animal were not able to do this.
It was already very clear that chimpanzees
don't have the kind of control over their vocal tract that we do.
So once people knew that chimpanzees couldn't produce speech,
the big question was why?
Scientists believed they knew the answer.
It was all down to our unique anatomy.
We have a larynx, or voice box, that's fixed low down in our throat.
This makes the vocal tract longer
and gives us the physical ability to produce a wide variety of sounds.
The voice box of all other animals was found to be high in the throat,
leaving them incapable of making the complicated sounds of speech
in their short vocal tract.
But nobody had actually ever seen inside the throat of an animal
as it vocalised.
Tecumseh Fitch had a unique piece of equipment
to solve the problem, a video X-ray machine
that had been developed to study animals swallowing.
What we found was really astounding.
It wasn't anything we were prepared for by reading the literature
and here's what we saw.
So what this is is the larynx pulling down out of the nasal cavity
so that during the vocalisation
the animal was vocalising out through its mouth.
The image made no sense so Fitch looked at other mammals,
including Megan the dog.
So you can see the dog's jaw and the tongue.
This is the larynx right here.
And you can see that with each bark the larynx kind of jerks down,
so let's slow that down.
So here's the larynx.
You can see that it's really a quite pronounced descent
of the larynx during the barks. It pulls down.
What Fitch discovered has revolutionised our understanding
of why we can talk.
The mammalian vocal tract is incredibly flexible
so whether we're looking at dogs or pigs or goats or monkeys,
we always see the same thing, that the, the anatomy
rearranges itself very dynamically while the animal is vocalising.
So it seems that if it was just down to anatomy,
all mammals would have the ability to talk.
The main conclusion that I draw from all this work is that the constraint
that's keeping a chimpanzee from speaking,
or indeed keeping a dog from speaking,
is not the peripheral vocal anatomy,
because any of these animals that we've looked at are able to lower the larynx
and reconfigure the vocal tract into a human-like confirmation
basically any time they vocalise.
So that can't be the main thing that's keeping these other animals
from having the capacity to produce humanlike speech,
so it must be in the brain, by process of elimination.
Come on, £4 a pound, banana.
Yes, I had to speak to both those...
Every dish has sugar.
We don't stop to think how our brain processes the 370 million words we will say in our lifetime.
Read my lips.
Or how we coordinate the complex sequence of thoughts,
movements and actions that lie behind each and every word we utter.
But if we are to ever truly understand language,
then it is deep inside our heads
where some of the greatest mysteries lie.
The more we uncover,
the more we realise how delicate and fragile these processes can be.
In 2006 Steve Steere was in an accident
that would change his life for ever.
Steve was always a very active person.
He had done two sponsored rides,
one to Mexico and one to Ecuador, which he thoroughly enjoyed
and he was training for the third ride, which was to go to Peru.
When he had an accident,
he was found unconscious and he was taken to hospital,
where they diagnosed him with a fractured shoulder.
Initially, Steve's injuries seemed relatively minor.
But early the next morning things took a turn for the worse
and he had a massive stroke.
This left him with severe brain damage.
He was told he'd never talk properly again.
I remember watching a programme
probably six months before Steve had his accident,
which showed a lady caring for her disabled husband
and I remember feeling,
"Gosh, if that happened to me, I don't think I'd be able to do that."
I remember sitting for about two hours in the room when he was asleep,
raging inside that this was not fair.
We'd just got our business going and it was doing really well,
and we had two young children
and I just think sometimes it's not fair.
Cases like Steve's offer scientists like Cathy Price
a unique window into how the brain and language connect together.
20 years ago I was told that the brain wasn't relevant
to our study of language
and the reason for that was that we had so little information.
The two types of information that we had were either from autopsies
of people who had died after they had had a language difficulty,
or we were using brain scans where the information was so blurred
that you couldn't really see very much detail about what was happening.
So at that point all we knew was that
the left side of the brain was most important for language
and the front part of the brain is important for speaking
and the back part of the brain was important for understanding speech
so that was the sort of general level at which it was understood.
As scanning technology has improved,
it's become apparent just how complicated the brain functions
involved in language really are.
Hello, Steve, can you hear me? That's great.
To build a complete picture of which parts of the brain
are involved in language in all of us,
Cathy Price matches the exact nature of a speech defect
with the exact position of damage in the brain.
When I look at Steve's brain here,
I can see that he's lost a very extensive set of regions
in his left hemisphere that are important for speech
and he can still produce some speech
but it will be extremely difficult for him.
A fully-fledged ability to communicate with language
relies on many separate processes working together within us.
We need to use our memory, our senses
and have precise motor control over our mouths and tongues.
What I'd like you to do
is to point to the picture that matches with the words, OK?
So the words are, "the pen is under the paper."
Cathy needs to identify the problems Steve has with speaking
before she can link them back to the precise areas in his brain.
This one. That's right.
When I ask him to point to pictures of particular scenes,
he could pick out which scene matched the sentence
and that's quite a difficult thing to do if you can't speak
because you can't hear the words go round in your head.
You can't repeat it to yourself.
So he did very well on that task.
The butcher shoots the nurse. Um.
It's a bit violent.
Yes. This one's a nicer one.
One crucial area of Steve's brain is still functioning.
The anterior superior temporal sulcus is involved
in understanding the meaning of words,
an ability that Steve has not lost.
But when we asked him to describe the picture,
then he had a lot more difficulty there.
Can you describe to me what you can see there?
Um.
What do you see here?
Um...
A cat.
That's right.
What's the cat doing?
Can you see what's here?
Yes.
Um...
Fish.
That's right.
Yeah, fish. That's right.
And can you see what the cat's trying to do to the fish?
I don't know.
What was happening was the cat was putting his paw into the fish bowl
to try and get the fish, and what Steve picked out on was the objects,
the cat and the fish, but not the action.
Book, the books.
And likewise with the books, the books were falling off the shelf
and they were about to hit the head of the sleeping man
and what he said was "books".
The head. Yes?
'And then all of a sudden, you know, he had a little breakthrough.'
Bouncing on the head.
Yes, excellent. That's very good, thank you very much.
Matching the problem Steve has in recalling words
with his detailed scan
has helped identify parts of the brain
involved in language in all of us.
This frontal area of our brain is associated with word retrieval.
Everything that he said and described indicated that he understood
what he was seeing but he just couldn't get the words out to describe it
in a way that you'd need to if you had to talk to somebody else.
By dividing the process of speech into such precise tasks,
scientists like Cathy are now piecing together
the first functional map of our language brain.
From an area that is crucial in allowing us to hear and monitor the sound of our own voice...
..to an area that is critical for analysing the very structure of speech.
There are all sorts of different components
that we're putting together to make this model
so it is like doing a jigsaw puzzle
where you have lots of different pieces and as you work on it,
you find new pieces but you also find,
"Ah I've got a little cluster of pieces here that now fit together
"into something very, very meaningful."
It's very much work in progress but we are building the clearest picture
ever of the areas of the brain that are involved in talking.
But how does it all begin?
COMPUTERISED VOICE: Hi, baby!
When does a new brain switch on to language?
COMPUTERISED VOICE: Hi, baby!
Part of our research
has to do with helping to understand the roots of,
of language reception
and how it is that babies begin to understand speech sounds.
Professor William Fifer works with new born babies to investigate
at what point they start to respond to the speech they hear around them.
Early experiments used an adapted pacifier
to measure how the baby's sucking responses changed
when it was played different voices,
but this technique relied on the baby being awake.
He now measures new born brain activity
using an array of electrodes
and he can do that even when they're sleeping.
So does this cute little baby have a name yet?
Liliana. Liliana. All right.
And what we're talking about today is how quickly she's picking up
information about language already.
So, as you know, she's been listening in the womb
and we think that she's particularly prepared
to want to listen to certain things, especially Mom's voice.
Sorry, Dad, but you'll come soon.
That's OK, don't worry.
She'll stop listening to both of us soon enough, we know.
Pfeifer wants to see how one-day-old Liliana responds to speech sounds
generated by different voices.
Her mother, a stranger or a computer saying the same thing.
Which in this case is "Hello, Baby!"
COMPUTERISED VOICE: Hi, baby!
Hi, baby! Hi, baby!
Hi, baby!
So when we do the experiment,
you actually can watch baby's raw brain activity right on the screen.
But later we process it to help us understand how much that baby is attending to any particular sound.
Pfeifer found that Liliana is able to respond to her mother's voice
in a way she doesn't to any other.
Hi, baby!
He believes the only explanation
is that she'd been learning from her mother in the womb.
Babies especially like to hear sounds that we call language
and it's those speech sounds that they've heard
that mother produced in utero
that later they'll learn carry information
that's going to be very important to them
but when they're first hearing these sounds they don't have any real meaning
but it's the quality of that voice,
it's the number of times they hear it, it's the rhythm, the cadence
that they're having some exposure to and we think that's what's affecting
their early auditory system so, as soon as they're born,
they cue in on that particular sound.
With his work, Pfeifer is showing that we are tuned
to the sounds of speech from the beginning of our lives.
'My baby's room will be yellow.'
BABY CRIES
Don't sound very good. That was too loud.
Yes, you didn't like her voice, no?
But this unique ability doesn't last for long.
THEY SPEAK IN NATIVE TONGUE
What is it that makes learning language so easy as a child
and so difficult as an adult?
DOORBELL RINGS
Hi, Chris. Hi.
How are you? Como estas? Estoy bien.
Christopher Taylor is helping to answer this question.
Chris is autistic and lives in a care home in North Yorkshire.
Despite being reliant on others for so many things in his life,
in one way Christopher is unique.
While he doesn't like talking to people very much,
he can speak more than 20 languages
including Welsh, Berber, Arabic and Icelandic.
Espanol y que otra lengua?
Que pasa aqui? How do you say zapatero in English?
Shoe maker. Shoe maker, that's right.
Language expert Gary Morgan
has been working with Christopher for more than ten years.
When I first used to talk to Christopher
and watch the way he plays with language,
the way he uses language, it was amazing.
I'd never seen anything like it.
OK, I've got some other papers here. Chinese.
Yeah. This is in Serbian. Vesti.
Serbian?
CHRISTOPHER READS IN SERBIAN
Learning new words is easy for Christopher.
And today he's meeting Gerardo who's going to teach him words in Nahuatl,
a language that's been spoken in Central Mexico
since the seventh century.
Y que necesito escribir?
Si, escribo. Este es una palabra Nahuatl
que se usan en espanol de Mexico y es papalotl.
Mariposa. Mm-hmm.
Christopher, when he hears a new word or hears about a new language
he doesn't know, he really gets excited.
It's what switches him on so, I think for Christopher,
languages are like collecting rare butterflies.
He likes to collect different languages,
different words in different languages.
Chris, you know these words that you learnt? Yes.
Just tell, just tell them to me again really quickly.
What was that one? Papalotl.
How do you say it in, in, in English?
Butterfly.
Chilli. Chapulin.
Cricket. Cocone.
Children, pepper, flower.
Oh, no lo conocemos, cochinilla, guajelotl.
Turkey. Aqualotl? Tadpole. Perfecto.
That's very quick. He does learn really quickly.
Christopher memorised all of the words he was taught
in just ten minutes.
His incredible ability means he's continually adding new languages
to the long list of those he's mastered.
I think Christopher illustrates the ability to, to learn rules quickly, the patterns,
scan through things quickly and see things,
predict what's going to come next in the language.
Christopher has this island of ability in a sea of disability
so everything else is poor compared with one unique ability.
The natural talent that shines through in Christopher
seems to be revealing an extreme version
of what might have once existed in all of us.
An innate ability for language.
Je m'appelle Frederica et je parle le francais,
l'anglais et l'italien.
HE SPEAKS IN NATIVE LANGUAGE
THEY SPEAK IN NATIVE LANGUAGE
D. D. Clever boy. Can you pick them up and tell Sylvie?
S for Sylvie.
What's that, darling?
Monkey. Yeah.
It was 50 years ago, the godfather of linguistics, Noam Chomsky,
revolutionised the field by suggesting that the basis of our language ability was innate,
built into each one of us.
Now let's have a look at the book.
He believes this explains why a child can learn language very easily
despite its complex nature.
It seems that the child almost reflexively picks up
specific characteristics of the language in question,
sound structure, pitch and so on,
and picks out its words and somehow knows what they mean,
and they mean very complex things.
That's mummy. That's the mummy monkey, so who's this then?
Daddy. Daddy. Daddy.
But all this somehow gets picked up very quickly,
which can only mean what it means in every aspect of biology.
It's just the way the child is designed.
Chomsky argues that our ability to talk
is not just the result of our general intelligence
but that we have an unconscious innate understanding about things
like sentence structure, word order, meaning and sounds.
Arlo, why don't you count them?
But while we may have the blueprint for language,
we need to be exposed to it early in life.
If a child is brought up on stilts, let's say,
and then they're taken off when it's two years old,
it probably won't be able to acquire the capacity to walk
because it's just too late.
You know, something should have happened already.
Same with binocular vision and so on,
and probably the same is true of language.
Chomsky's theories get to the heart of the fundamental question -
is talking the result of nature or nurture?
It's a problem that's notoriously difficult to unpick.
One theoretical solution that has enticed scientists for many years
would be to isolate a child and raise them in silence.
Would the child develop language on their own?
Because of the cruelty involved,
scientists could never carry out this test on humans.
It's become known as the Forbidden Experiment.
The best scientists could hope for
would be to find real live case studies,
feral children, those brought up by animals in the wild.
If children raised away from human contact could be found,
how they communicated could finally answer the question
of whether the ability to talk was innate.
In 1991 the scientific community
believed they'd stumbled across such a child.
SHE BARKS
Eight-year-old Oxana Malaya was found in the Ukraine
and she'd been raised by dogs.
They were surprised to find
that while she behaved like the dogs she lived with,
even barked to communicate...
SHE BARKS
She did speak some human words.
The findings seemed to suggest that despite her circumstances,
Oxana had an innate ability for language,
one that was nurtured after she was found.
SHE SPEAKS RUSSIAN
But it later emerged that in her first three years
she lived in a domestic setting and had had human interaction.
It meant the scientists were no closer to establishing
how much of our ability to talk is innate.
The Forbidden Experiment has remained enticing but out of reach.
Until now...
One scientist has found a unique way
of getting round the ethical problem.
Ofer Tchernichovski is studying something linguists
think might hold the key to whether speech and language is innate.
The Forbidden Experiment is trying to see what speech and language
human infants will develop without any exposure to spoken language.
Of course, this cannot be done in humans
but why shouldn't we do it with birds?
Zebra finches are perfect subjects.
While the females don't sing at all,
the male chicks learn to sing by imitating their fathers,
just like human children copy their parents.
To recreate the conditions of the Forbidden Experiment,
Ofer and his team isolated male chicks away from their fathers
before they were taught to sing.
Kept in isolation in specially sound-proofed cages,
their song developed to no more than a croak.
One of these isolated males was added to a group of females
to create a new finch colony.
Ofer hoped that the females would find
the male's call attractive enough
that they would mate and create the next generation.
In the beginning, the first problem that we had is that the females
were not very interested in the isolate male.
When he start singing his isolate unstructured song, they say "yuk!"
And they wouldn't go with him.
But, we didn't let go and we kept going like that with a few tries
and in the end one female became desperate enough
and mated with the isolate founder,
and then we had baby birds that imitated their father.
The young birds instinctively copied their father's song
despite its unstructured unattractive sound.
And interestingly enough,
in isolate song we see song that may be more prolonged.
We can see syllable that go like "Waaaaah" like that
instead of "choob-chab-choob."
And this is something that they were still imitating
so they were listening to that tutor that was singing abnormal song
and they imitated his abnormal song, and so did their children.
That in itself was not surprising.
The sons were tutored by their father.
But when the researchers compared song over the generations,
they saw something extraordinary.
Each new generation of birds didn't just imitate their father's song.
They also improved it.
By the fourth generation,
the finches were singing a version of the song that normal birds sing,
despite none of their colony having ever heard it.
We were very pleased to see how quickly normal songs start emerging
out of those very unstructured songs of the isolate
and that individual bird has this ability to imitate and to improve,
and improve at the level that he makes the song more species like
and perhaps more effective.
To adapt a song without being taught how to
means the finches must have some innate ability.
In the bird, seems to be somehow encoded
so that when they imitate sounds,
they'll shift them to where some kind of an internal image
that they have of how a good zebra finch song should be like.
Ofer's work suggests humans might also have
this innate ability to talk.
If we'd never heard speech,
we'd develop a form of language within a few generations.
After 50 years of research delving into our brains.
Hello, Steve, can you hear me?
Observing the birth of language in children.
Hi, baby!
Studying song birds and investigating anatomy...
Scientists have come to the inescapable conclusion
that we're built for speech,
and that can only mean one thing.
The origin of language must lie in our genes.
It would be like looking for a needle in a haystack.
THEY SPEAK IN NATIVE TONGUE
Unpicking the genetic component of language is a huge challenge.
From the thousands of genes that make up the human genome,
it seemed almost impossible to identify a gene that has
an influence on the multitude of functions behind speech.
But 20 years ago Faraneh Vargha-Khadem,
a neuroscientist from University College London,
was introduced to a British family
that had a very unusual speech defect.
A family who would help solve the mystery of how we speak.
When they are speaking they give the impression that they are deaf,
but in fact they are hearing individuals
but they give the impression that they are deaf
because their speech is not clear
so people have got difficulty understanding them.
When our children was born,
they found it very harder, or severe, for talking.
But some people at school would take the mick out of me.
Faraneh and her team spent several years testing the abilities
of affected and unaffected members of the family
so they could fully diagnose the condition.
To protect their identity, they were named the KE family.
When it comes to the KE family members who are affected
with this speech and language disorder,
they're very normal in every other way.
They, of course, have a very specific speech and language problem
but their thought processes and their communication abilities
in other ways are perfectly normal.
Hoping they would find a link between affected family members,
a geneticist joined the team.
The family at the time consisted of 30 members and 15 of the members
had inherited a speech and language disorder from the grandmother.
The first genetic study
was able to locate the general area of the abnormality.
It was on chromosome 7 and all the affected family members had it.
Reflecting its obvious importance in their ability to talk,
the research team called it Speech 1.
Speech 1 was located on chromosome number 7
but where exactly on chromosome number 7
and which particular gene was it,
was something that would have required
several more years of investigations
until the actual gene was detected.
Then, out of the blue, a totally unconnected child
with the same type of speech defect was brought in to see them.
And when you think that in this big wide world,
the same kind of problem presents itself in the same country
in the same location but to the same person!
So you really have to recognise that there is a huge element of luck
that was involved in allowing this discovery to be made.
Finally, they had the breakthrough they needed.
Tests on the new child's DNA
revealed that part of his chromosome 7 was clearly broken off.
And to their amazement, Faraneh and her team
found a mutation in the KE family's DNA, in exactly the same location.
That finding suggests that many people with speech disorders
could have a faulty gene.
After years of searching, they'd finally found a gene,
one that controls our unique ability to shape words.
They called it FOXP2.
FOXP2 seems to have a very important role
on the control of this part of the face
in order to be able to communicate the tiny movements
that are required in order to sequence the speech sounds
that results in our fluent speech.
HE SPEAKS IN NATIVE TONGUE
Your ability to talk.
De la tua capacitad di parlare.
The discovery of FOXP2 in humans
marked a significant step forward for linguistic science.
One family had unlocked some of the key secrets of speech in all of us.
This kind of a connection between a single gene
and a cognitive capacity,
like speech and language, is quite remarkable to be able to demonstrate.
It was later discovered that all vertebrates
have a version of this gene
but just two tiny changes in the human form
has meant the difference between making noises and producing speech.
It looks like this period where these changes occurred
may have coincided with the time that modern humans had come about.
The effect of these small changes in our genes was massive
because, for the first time,
we were able to manipulate our mouths to form complex sounds.
Once we had the anatomy and physiology required for speech,
we were primed to talk.
Enriched their lives enormously. I don't know why I said it.
To create everything that exists up till now.
But when did we actually start to speak?
The dawn of speech is one of the great puzzles of evolution
because there's no fossil record of verbal communication
for scientists to look back through.
Mark Pagel is an evolutionary biologist
on the hunt for the origins of language.
There's a lot of ideas about this.
They're all speculation
but they rely on having the right genetics in place
and having the right anatomy in place,
and we know that by 200,000 years ago,
both of those things were available.
We may have been physically able to speak
but linguists believe it's more likely that the birth of language
coincided with the proliferation of man-made objects
around 50,000 years ago.
At this time there was an explosion in art and technology.
We start to see, for the first time in the archaeological record,
lots of different tool types, lots of different implements,
lots of different huts that people lived in
and so these things seemed to appear rather abruptly,
suggesting that there was some change in the way we lived.
Many scientists think that the birth of language
instigated this cultural boom.
But without a time machine,
we may never know exactly when we started to talk.
But what we do know is why.
Mark Pagel believes that language probably developed
as a practical way of defining roles and it formed a kind of social glue.
We had something that no other animal does and that's what humans do
is that they divide up the tasks.
So, early in our evolution, somebody might have been gathering wood
while another one was gathering water.
Somebody might have been making the huts
while someone else was making spears
and, at the end of the day, all those tasks are shared
and I think we can start to see that we need language to regulate that.
We need language for people to be able to talk to each other
about what they're doing and to be able to represent what
their contribution is to the society as opposed to everyone else's.
This motivation to clarify social tasks
was the final push we needed to get us talking.
How we adapted the first sounds we made into language
is now being revealed for the first time.
Because no-one designed English, say,
no-one sat down and thought, "English would be useful
"if it had relative clauses
"or some other piece of grammar," it just happens,
it happens by this blind unconscious process of transmission
and, for the first time,
we're able to see that happen in the laboratory.
Renana.
Nepilu.
Can you remember this language?
Lapiranana.
It's one you've never seen or heard before.
Kisafiki.
It's been created by Simon Kirby
and is made up of words that describe alien fruit.
Neheki.
Kirby and his team have devised an experiment where they can watch
this language evolve over hundreds of years in just one afternoon.
Nahuna.
We start the experiment with this garbage language,
this random language.
In fact, to call it a language is, is in some sense misleading.
It's not even a language.
Nereki.
In the beginning, the alien words are completely random.
Pilu. With no common factors between them.
Lapalu. Kirby's guinea pigs have to familiarise themselves
with the new words before being tested to see what they remember.
But there's a twist.
Some of the fruit are familiar
but half of them have never been seen
and the volunteers couldn't possibly know the words that describe them.
Something most of them don't even notice.
Kinamula.
Neki.
The early participants do very badly in the test because the language is completely random and unstructured.
Unfortunately you didn't get any of them right. Oh, my God! Sorry.
It was really hard. I just couldn't seem to find any patterns.
I thought I'd be able to see a pattern with maybe the colours
and I put in key or ka for yellow
and then maybe I thought lu could mean two.
It was a bit of a shock to hear I hadn't seen half of the language.
I just felt a bit cheated, really! I didn't have a chance.
Napilu.
But the experiment doesn't end there.
All the words produced by the first candidate
are used to create the language for the next person in the experiment,
including the words they invented for the unfamiliar fruit.
Each of these learners thinks that they're giving us back
the same thing that we trained them on, as best they can,
but in fact each of them, unconsciously,
is changing that language, changing it piece by piece over time.
Nahuna.
As it's passed through generations of users,
the language slowly turns from a random chaotic one
to one of structure with combinations
that can be easily remembered.
By the ninth generation, the words have been divided into parts
and each of these has a different meaning.
N, L and R describe the different colours.
The middle of the word describes the number,
and the end of the word like "plo" or "pilu"
describes the type of fruit.
This allows the parts to be joined together in different ways
to describe fruit the volunteers have never seen before,
a crucial feature of human language.
I think lahoki will be this one.
Got all five out of five right. Oh, good, excellent.
The really striking thing that we've discovered
is that when we run these experiments
what we get at the end looks like a real language,
not one of the languages that we see in the world today
but it looks like a language in that it's got those
essential defining characteristics that we see in language.
In other words
these languages that emerge are made up of parts that can be recombined.
This happens gradually, it happens without anyone knowing it
and yet it is the exact feature of language that makes it unique,
makes language different from everything else we see in nature.
Renana.
I'll do it in Catalan.
It's this ability we have to combine sounds to make new meanings
that means how we talk will continue to change
from generation to generation.
That's mummy.
And the fact that it's a living entity makes it so fascinating
but so evasive for scientists.
We have come a long way but, at the same time,
it's really a window that has opened.
We are only beginning to get a glimpse
of how complicated the whole process is.
Researchers are beginning to understand
that, beyond our innate ability and our upbringing,
there are more factors that influence why we talk.
One area of growing consensus in understanding the biology of language
is the realisation that language actually is not one monolithic thing
but instead is made up of multiple different components.
Come on, £4 a pound, bananas!
BABY BABBLES
HE SPEAKS SERBIAN
We talk about the innate abilities and the learnt abilities,
what we inherit and what we acquire, what we're given by our culture,
our society, our parents, and what we get from our genes.
Chapulin. Cricket.
Cocone. Children.
I think both of those abilities, both of those sets of things
need to be in place for you to have the full,
fully-fledged abilities with language.
And being able to identify all these components
and understand how they fit together may tell us what it is to be human.
A cat.
And somehow out of this complicated soup of interactions between people,
language emerges, and that's really what we need to understand
if we are to understand where language comes from
and why it is the way it is,
and it's a really difficult problem.
But answering the problem is important because
it defines us, it defines who we are.
Nehilu.
Subtitles by Red Bee Media Ltd
E-mail subtitling@bbc.co.uk