What you are about to see is one of the miracles of nature,
the extraordinary transformation that will turn this caterpillar into a butterfly.
But we human beings go through a transformation that is just as dramatic.
0ver four agonising years, our bodies and minds are transformed.
At the end of it, like the butterfly, we'll be sexually mature.
This incredible change is called puberty.
Best thing about puberty? That would be my voice getting deeper.
Girls start liking you and you start liking girls.
It's very interesting. I like it a lot.
Worse thing? God!
The worst thing for me is the ups and downs of life:
having to deal with acne and hair and stuff like that.
I don't have any facial hair, so people start to compare me with those who do.
It's like a rollercoaster.
You don't know where it's going to turn. You could go a good way, a bad way.
Just dealing with it is a drag.
# Let's talk about sex, baby,
# Let's talk about you and me,
# Let's talk about all the good things... #
Unlike caterpillars, these teenage boys have no cocoon to hide in
while they travel from childhood to adulthood.
We all make the journey, and it can be a bumpy ride.
We often have the illusion that we're in control of our bodies.
The reality is that it's usually our biology which controls us.
That's particularly obvious during the great rollercoaster ride of puberty.
We don't precisely know when it's going to start,
we don't even know how long it's going to take,
and although we think we know what's going to happen,
nothing can quite prepare us
for exactly how we're going to feel.
It feels exciting and dangerous and you don't know where the next shock's coming from.
And the worst thing is that just as you think you've mastered it,
suddenly something else happens
and your body changes again.
If living through puberty feels like a horror story,
the villains of the piece are hormones.
These tiny chemical messengers are beyond our control.
Suddenly hordes of them start racing through our bloodstream, ordering our bodies to change.
They tell us to switch on to sex, getting us ready to make babies.
They tell our muscles and bones to get bigger and stronger.
They make hair sprout in unusual places.
Sometimes they really let us down.
Amazing though it seems, hormones will affect our brains, too.
They'll make us think about new things.
We'll think about them in a new way.
The result in the emerging adult is confusion and defiance.
But eventually as physical, emotional and sexual maturity.
Go on!
This programme tells the story of the human body's enormous changes during puberty.
It's also about what it feels like to experience puberty.
- All right now. - Is that with Doris Day?
We followed a group of teenage boys in California,
and we've done something unique.
For a crucial eighteen months of her life,
we've watched and listened as a British girl goes through the ups and downs of adolescence.
Now, she's on the threshold of adulthood.
But when we first met she looked and felt very different.
My name's Beatrice. I'm twelve years old. My birthday's in November.
My parents are divorced and I live with my mother and stepfather.
My mum's a councillor and my stepfather is a solicitor.
Sean, shut up.
At twelve years old, Beatrice is a success.
It's not just that she's bright and likeable.
In terms of biology, she's done everything a child should do.
She's survived her most dangerous moment, her birth.
From being a helpless baby, she's gained control.
She's learnt to walk and talk
and to cope with the complex social world around her.
Thanks a lot.
But she's all too aware of what her future holds in store.
When you're a teenager, apparently you go bolshie.
You get periods, you get pubic hair, you get taller.
You get sort of...you get wider at the hips, I think it is, I can't remember.
And you get breasts and all this.
And I don't know, I just...
I just don't want it to happen, really.
(TEACHER) Remembering back to your achievements last year,
when you won the, was it cross country?
(BEATRICE) I'm quite happy with myself the way I am.
And I don't know, I mean, I'm quite happy being a kid.
But however unattractive the prospect of leaving childhood is,
in one way, Beatrice is very lucky to have had one at all.
Human beings are unique in the way they linger as children for an extraordinary long time.
If Beatrice was any other animal,
she'd have stopped being a kid a long time ago.
It's a bit of a puzzle, because other animals mature very differently.
This is Nica. She's a Bengal tiger and she's just 13 weeks old.
For her, like most animals, the journey from babyhood to full-grown
happens as one continuous process.
In about three years time, she'll be able to have cubs of her own.
If I'd grown in the same way,
I could have fathered a child at the age of four,
and would be completely grown at the age of six.
The reason I didn't do that is because the human body does something very unusual.
It breaks the journey from baby to sexual maturity when we're tiny, just six months old.
And though we keep growing, we wait more than a decade to gear up to have children.
For Nica's ancient ancestors,
spending ten tiger years without getting ready to have sex and make cubs
would simply be a dangerous waste of time.
But for our ancestors, things must have been quite different.
They needed time for something so vital to their survival that even sex could wait.
That something is quite surprising. It's learning.
Nought times six is nought.
One times six is six.
Two times six is twelve.
Wherever you look in the world, all children have to learn the skills they need for survival.
Not just the obvious ones, like making yourself understood,
but the things we don't even think of as learning at all,
like walking and controlling our bodies.
As children, we can learn faster than we'll ever be able to again.
Magnified ten thousand times, this is a single human brain cell.
Your brain has a hundred billion of them.
Every one is connected to thousands of others through their tiny branches.
Each join adds a little bit more to the intricate picture of who we are.
As children, the connections are still being made.
Like a plant exploring its surroundings,
brain cells like these are growing their branches,
constantly reaching out to each other.
Learn to ride a bike and you wire up a tiny part of the brain.
Learn a new word or how to catch a ball, and you forge new links.
And with difficult tasks, like writing,
it's only by doing the same thing over and over again
that the connections are made strong.
In the end, they take root and stay with us for the rest of our lives.
But though learning is so vitally important,
there comes a time when our bodies have to move on,
and the rollercoaster of puberty lurches into action.
We don't know what exactly decides when that should be,
but we do know that when it starts it's the brain that's in control.
Peering deep inside the head, you can see where it all happens.
Shaded white, it's the body's autopilot,
a tiny gland that constantly adjusts things like temperature, blood pressure, thirst and hunger.
It's called the hypothalamus and it's the driving force behind puberty.
From its position in the centre of the head,
it can control parts of the body far away and it does so with a remarkable trick -
by dispatching highly efficient chemicals into the blood.
These chemicals are called hormones, and each carries a different message.
For example, adrenalin makes you run faster just for a moment,
but the hormones of puberty change your life forever.
This system is so sensitive that even minute amounts of hormones make massive changes.
If my taste buds were as sensitive,
I'd be able to detect a pinch of salt in a swimming pool.
You can't see hormones in the blood,
but take them out of the body and they're suddenly revealed.
Each one is a uniquely-shaped molecule which, like a key in a lock,
can fit into specific receptors all over the body.
They're subtle and they're in control...
and at the start of puberty they come out at night.
In the restless nights of early puberty,
Beatrice's brain dispatches its chemical messages every ninety minutes...
and her body listens to the signals carried in her blood.
Not just to the amount of hormones, but to the patterns of their release.
In a boy, it will be the testes that pick up the signals.
In Beatrice, it's her ovaries.
The ovaries and testes spike the blood with two potent ingredients,
oestrogen and testosterone.
Circulating everywhere, from head to toe,
these are the real heavyweights of puberty.
They make the rollercoaster an unpredictable and emotional ride.
Some days you feel like you're the bomb,
like everything in your life is going great,
you can't expect anything more.
And then it feels like you're nothing, like you've made mistakes,
that it's over and stuff, that you might as well give up,
and then it goes back up and then it goes back down.
It's always up and down, up and down.
It's never a straight line or inclining up, it's always bumpy.
Beatrice, too, can't control the journey she's on.
Biology has taken over, and the hormones inside her have reached critical levels.
Her body is now being rebuilt around her.
I don't like the physical side of it.
I just wish it appeared one morning, but then that would be a bit awkward.
Your upper body begins to...
You get pubic hairs and that's a right bummer.
And then you, I don't know, you get larger in different places and smaller and whatever.
(D0CT0R) Big breaths in and out.
There you go.
Lovely, right. Let me swivel round and I'll sit in front.
- How old are you now, Beatrice? - Thirteen.
Thirteen? Right. Can I listen here?
I haven't got hips yet, but I'm supposed to get hips.
I don't know whether I want hips or not.
That's lovely, well done.
And just pop it round here.
Have you put much weight on recently?
- No. - No?
I don't know, I don't think so.
0ne of the remarkable things about puberty
is how different the changes are in boys from girls.
Take this perfectly ordinary family.
There's a vast and pretty obvious difference between Mum's and Dad's bodies.
Yet the two children are surprisingly similar.
Christopher and his sister Kerry are seven and nine.
Until they reach puberty, their chests are biologically identical.
So what makes them change in such different ways?
It's those hormones again, which arrive in very different combinations.
Girls' bodies are flooded with oestrogen and their chests respond.
Across the world, there's a huge variety of size and shape,
but every woman's breasts go through the same stages of development.
First, the cells which will eventually make milk ducts start dividing.
The dark area around the nipple begins to grow.
Within months, the breasts start expanding.
Fat is laid down as the adult shape forms.
It'll be around four years before the skin around the nipples lies flat,
forming the smooth contour of the adult breast.
It's painful to run, let me tell you that.
Because what happens up above, you have to start wearing a bra.
Sorry, had to mention it.
It gets really painful to run.
Bras are really, really uncomfortable.
It's just like having a strap put across your chest, permanently.
But just getting breasts is not the end of the story.
They will grow again during pregnancy
and only after a woman gives birth will they be fully mature,
when in most cases they start producing milk.
While a girl's body begins to change shape,
a less obvious, but more important transition is taking place deep inside her,
in her ovaries.
The size and shape of a walnut, these two off-white organs rest either side of the pelvis.
Not only do they produce the hormones that drive puberty,
but they contain the raw material of new life - a woman's eggs.
More than a hundred thousand in each one.
From puberty, once a month, one of these eggs will be set free.
Carried inside the Fallopian tube,
it takes the egg three days to make the 15 cm journey from ovary to womb.
Meanwhile, the womb prepares for a possible pregnancy.
Its lining thickens, ready to be home for a fertilised egg.
This is it, ten thousand times larger than real life.
A strange and dramatic landscape.
A food-rich bed, up to a centimetre thick.
Its only purpose is to nurture new life.
But if the egg is not fertilised, the bed is not needed.
These remarkable pictures reveal the cervix, the opening of the womb.
They show the lining, unused, beginning to flow away.
In her period which follows,
the average woman will lose an eggcup-full of blood.
I don't want to get periods.
I'll tell you why, because people tend to get moody.
One of my friends has got her periods and she gets really, really moody.
And some people get pains and I don't know if I will. I hope not.
I don't like the idea of getting my periods or whatever.
Like it or not, once the rollercoaster starts, there's no stopping it.
With hormones pulsing through her every day, Beatrice's body races ahead out of control.
Yet it can all seem painfully slow.
You know, I wish, I just really wish that it just appeared one morning,
that you went into a little cocoon and woke up and it was all there.
And you were used to it.
Not it happening over three years.
Or four or five or whatever it is.
One of the things I like, everyone used to be taller than me.
Now, lots of my friends are still taller than me, but mostly adults are really short.
I like the fact I'm taller than a lot of people, and being bulky and big, too.
Boys' bodies too, are growing faster than at any time since they were toddlers.
It's easier to develop your body, too, when you're in puberty.
When you're little and you work out, it doesn't show up so much.
- It takes less. - Yeah, yeah.
You start eating a lot, you eat a lot.
Then you start getting bigger and you feel other things getting bigger, so you feel manly.
All the changes they experience are driven by their own sex hormone, testosterone.
And it's made in the testes.
As puberty starts, the testes begin to grow.
It's the first outward sign that anything is happening.
The skin of the scrotum gets rougher and there's a wispy growth of pubic hair.
Inside, the testes are a tangle of tiny tubes,
miniature factories that will soon start to churn out sperm.
And they'll do it on a massive scale.
A thousand every second.
Shortly after the testes start growing, the penis itself starts catching up.
The skin gets darker,
and in four years the machinery of reproduction is complete.
With a special camera that shows heat as colour, we can see why the testicles are where they are.
The red and yellow of the tummy show that it's hotter than the bits coloured green and blue.
Sperm factories work best when slightly cooler than the bulk of a man's body.
Hanging low keeps them cool.
And it's now, of course, that the penis starts getting up to some new tricks.
I had one first erection when I didn't know what it was.
Then I had a first erection where I knew what it was.
- One that I didn't know what it was... - That's the first one.
-The first one, you didn't know what it was? - Right, right.
- The second one, you knew what it was. - Exactly.
- The first one... (LAUGHTER)
It was, like, pulsating. Bedong! Bedong! Bedong!
I'm sitting and I have to use the bathroom.
I really had to piss, 'cause I didn't know what it was.
Inside, the penis is made of a spongy tissue filled with thousands of tiny blood vessels.
Normally, blood flows in and out at a constant rate.
During an erection, blood flow increases dramatically.
Blood vessels at the base of the penis are squeezed.
Blood still flows in, but it can't get out.
Pressure builds up.
The thermal camera shows the heat produced by all that extra blood.
And, to the horror of its owner, the penis seems to have a mind of its own.
I don't like it when you get an erection in class.
You're sitting like...
- So you try and hide it. - I try and tuck it under my belt.
- Yeah? - I fix it up and try to hold it down.
These involuntary stirrings happen as the body learns to control its functions.
But there's still one more surprise in store.
It was in sixth grade, I was watching TV one night and I saw this foreign girl,
and it was some movie where there was this really nice-looking girl,
and I thought she looked good.
I dreamed about her and I woke up in the middle of the night,
and something was wet on my pants, on my boxers.
I had Sex Ed a little before that so I knew then I was OK.
- I'm ready to be a man! - Now I gotta clean it up.
- And change my boxers. - That shit's sticky!
- Not on my bed, just my boxers. - That's horrible!
This is a view inside the sperm ducts.
It's unlikely that the boys' first wet dreams contained any sperm at all.
It takes time for the machinery of production to crank up.
And the first few times, it's firing blanks.
Even when the system kicks in, most of the fluid isn't sperm at all.
It's a liquid which both protects sperm from the acid of a woman's vagina
and gives them energy for their long swim ahead.
But once the sperm factory is up and running, there's no going back.
A man will go on producing sperm for the rest of his life.
Quite apart from the physical transformation they bring,
hormones trigger a much wider change.
They influence teenagers' whole outlook on life.
(BEATRICE) My mum says that I wear too much black.
(GIRL) How can you wear too much black?
I think the tie-dyed, try on the smallest one.
For Beatrice and her friends, this means experimenting,
learning to take charge of their lives,
trying out attitudes and opinions to see if they fit.
You might as well wear a couple of wires joined up.
- Might as well wear a bikini. - It's basically see-through.
(GIRL) I don't know why they have so much decoration.
(BEATRICE) Who'll see them? Your husband? Your...?
- What d'you think? - Yeah, I like the top.
- Wonderful, yeah. - Ooh, nice, Kerry.
I quite like that, I'm sorry. This might seem extremely sad, but I like that.
Just as the body is test-driving its systems,
the brain is beginning to explore its new world.
She's become, since the summer, significantly more independent,
but still likes to have us around, I think,
in the background so we're there, but she's doing her own thing,
so she's got some safety, I suppose.
OK! What d'you think?
The top, not the skirt, the top, not the skirt?
She was very proud of me because I caught the train by myself to Southampton.
And it was a big achievement.
She's quite testing in the sort of questions she asks and her opinions.
She's got lots and lots of opinions about things
that all come from outside or come from school, and that's all quite different.
Teenagers, notoriously, want to break free from their parents.
Their rebellion can cause pain all around.
- Uhh! - OK?
Oh, my ear! I can't hear!
- OK? - OK.
Not too bad, was it?
But children are only doing what's needed to maintain the next generation:
learning to become effective parents.
They're beginning to look after themselves
and recognise the responsibilities of adulthood.
Emotionally, you get down on yourself more as a teenager when you're sixteen,
than when I was eleven.
Usually, I didn't have anything to worry about when I was eleven.
But now I have a lot of stuff to worry about in life and stuff -
girls, parents, teachers, school. So that's a lot of difference.
When I was eleven, I had more people watching me and making choices for me or with me.
Now it's more by myself, with a little help.
In future it'll be by myself.
Many of the changes in puberty are quite subtle.
But one is blindingly obvious.
We just grow much bigger.
And how that happens is really rather surprising.
To reveal the secret of how we grow, we need to look at my own bones.
This scanner produces a magnetic field ten thousand times greater than the Earth's.
Enough to see right through me.
My hand and wrist are an intricate mesh of tightly-packed bones.
If you could have seen them when I was a child, they would have been very different.
This X-ray study is unique.
And going backwards over twenty years reveals a remarkable thing.
The hands of children are not all bone.
There, for instance, no knuckles.
And there, look at the gaps in the wrist.
Instead of bone, there's cartilage, something the machine can't see.
0nly when cartilage turns into bone can the the hand grow.
And how does this happen?
It's hormones again.
Puberty pumps them out and joints get bigger and limbs get longer.
By the end of our teens, there is no more cartilage and there can be no more growth.
Boys and girls have two distinct periods of growth.
When we are children, our bodies grow in a more or less constant way.
Boys are generally no taller or stronger than girls.
But at puberty all that changes.
James and Annie are brother and sister,
but James, a year and a half older than Annie, is a good ten centimetres shorter.
A lot of my friends are shorter than me, but a lot are the same height.
So, I'm not exceptionally tall, and he's not tall.
He just don't grow.
- Shut up! - You don't, you look freaky.
You've been that height for about a year.
What makes Annie taller at the moment
is that girls get their growth spurt at the start of puberty,
while boys get theirs at the end,
which could be as much as three years later.
But James needn't worry.
Starting late means starting from a taller base.
So, like most boys, he'll end up bigger than most girls,
and that probably includes Annie.
From having very similar body shapes, boys and girls now follow very different paths.
A girl's shape changes to get ready for bearing children.
The hip bones spread outwards and become flatter.
But more important is what happens to the space in the middle.
It opens, ending four centimetres wider than in men,
just enough for a baby's head to squeeze through.
The changes in a boy's body stem from his need, in times gone by, to be strong.
The testosterone in his system has dramatic effects.
His heart and lungs get bigger.
With each breath, more air travels down his windpipe.
Through a mass of tubes, it ends here,
in the three hundred million air sacs that make up his lungs.
0xygen passes through the membranes and into his blood.
The more that gets to his muscles, the faster he can run.
At the same time, the mechanical parts of his body are adding to his power.
Here we can see the complex array of muscles and tendons that hold the knee together.
Watching how they move reveals how impressive the human body is.
The two bones don't actually touch.
The soft tissue between them allows them to move in a smooth and precise way.
This whole physical system gets better as muscles and tendons grow larger and stronger.
There's another change at puberty that you can hear easier than you can see.
But I'm going to try and show you with this.
Looking across the tongue and down the throat, these are vocal chords.
The whiter bits in the middle make sound, vibrating furiously when air flows past.
I can alter pitch just by changing the tension of the chords.
Tight for high notes.
0oohhh.
Slack for low.
Aaaawww.
In boys, the whole set-up grows.
You can see it from outside.
Vocal chords get longer, voice chamber bigger,
sending a man's voice an octave lower than a woman's.
Most of the time, this change happens gradually.
But the transition is huge.
The brain is having to re-learn all the intricate muscle controls it uses to make our voices work.
It's like having to learn a new musical instrument,
but sometimes even the brain can hit a bum note.
I hate it when your voice starts getting lower,
- and you start cracking all the time. - Yeah, yeah, yeah.
I say something to my mom or something,
I'll say it all squeaky and then it turns back deep.
- And...um... - It echoes.
Sometimes I can't control it. It just happens.
With all those hormones wreaking havoc inside us,
the body chooses now to confront us with one of life's trickiest challenges.
Sex!
I want you to tell me the first thing you think of when you hear that word, sex.
- Just shout it out. Steve? - Boys and girls.
Boys and girls. Nice and loud, shout 'em out.
- Orgasm! - Pregnancy!
- Pregnancy. - Positions!
- Diseases! - STDs!
It's no accident that teenagers seem to wake up one morning thinking of nothing but sex.
What else do you think of when you hear the word sex?
- Lust! - Lust.
- Trust! - Erection!
When we're children, sex, for the most part, passes us by.
But in puberty the amount of oestrogen and testosterone
pumping through the blood rise month by month.
When they reach a critical level, they seem to affect the central part of our brain.
This is the part responsible for our feelings and desires.
Sex on the brain, one-track minds, that'll be our hormones.
You know a word that I don't see up here?
- What? - What?
(WH0LE CLASS) Love!
Why is that the last thing some people think of, instead of the first thing?
Good question.
The answer seems to be that teenagers' physical development runs ahead of emotional maturity.
The body has sexual urges that the mind can't deal with.
And while it's catching up, there's plenty of scope for turmoil.
Guys shouldn't be as nervous as some are towards girls,
because girls in the long run want the same thing.
And so they should be more outspoken,
and should just come forward and say what they feel and say what they mean.
I think first of all, it's physical.
I think that's what you notice first. You don't look inside a girl and say,
You'll look at her because you like what you see.
I think after you go out with them for a couple of times,
and you get to see what they're really thinking, that's when you decide that's the girl you want.
(UPBEAT S0UL MUSIC)
Perhaps it's one of nature's little jokes.
Just as we're really growing up, and how we look is as important as life itself,
our body starts playing tricks on us.
(B0Y MAKES D0G N0ISES)
Are you guys gonna dance at the party?
No sooner have we begun to take an interest in the opposite sex
than we're hit with strange growths that do nothing at all to help romance.
Zits, two of 'em...three of 'em.
They're a teenager's worst nightmare, and they serve no useful purpose.
The upper body is covered in oil glands.
They're a leftover from our hairy past when they kept our hair sleek and waterproof.
I hate my spots, I really wish I didn't have them.
During the onslaught of puberty, these glands go crazy.
They produce a sudden rush of oil with which our skin can't cope.
The oil blocks the ducts, trapping bacteria
and provoking those nasty but irresistible spots.
And at puberty something else grows.
The sudden appearance of hair is one of the more visible signs of maturity.
Quite why it sprouts, in just a few small patches,
is something of a mystery.
Bizarrely, the answer is probably sweat.
0n most of our body sweat is water-based.
It helps cool us down when we overheat.
But where we have our hair, sweat is different.
It's thicker and milky.
It contains fat and gives off its own smell,
which some people believe makes us attractive to each other.
You smell more. Like musk.
- Body odour. - Yeah.
Y'all funktify.
Body odour is one stage further.
Bacteria love fatty sweat.
If it stays around for long, they'll happily rot it away with alarming results.
I reckon we should tell her about her BO problem.
0ddly, while the rest of our hair varies from person to person,
pubic hair is nearly always the same,
thick-stranded, short and curly.
It's like a forest, like a wilderness.
This hair, magnified 400 times, shows you why.
The hairs aren't round, but flattened.
They've been squeezed by the hair follicle
so as they grow, they spiral.
But why aren't pubic hairs much longer?
They grow for just six months.
So when they die and drop out, they're still quite short.
If they were like head hairs, they'd grow for seven years
and we'd all be in trouble.
It's a bit irritating sometimes.
Especially when you have to do that first bikini line.
It's now almost a year since we first filmed Beatrice.
In that time, the hormonal cycles driving her body towards maturity
have been getting stronger.
Now, the one change Beatrice has been dreading has arrived.
Yeah, I started my period, and it caught me completely off-guard.
But I was all right.
She was very matter-of-fact about it, more so than I was.
She let me know by ringing me at work, and she said,
The good news was that she was going to be in a top stream.
And then she decided to go out and celebrate,
but we didn't go out. She baked a cake and bought me some chocolate eclairs,
which was very nice of her.
Quite a lot of people I know celebrated when they got their period.
It seems strange, but, hey!
(BEATRICE'S M0THER) She's sort of ambivalent about it.
I think she's rather proud to have her periods.
At the time, I felt quite tearful, quite sad about it.
I didn't talk to her about that because I felt it was really the end of my little girl,
even though she's not little any more.
But it was an absolute, this is it now.
The good part of it is I know I'm perfectly normal.
I know I'm a girl, I'm a female.
Then, it's the fact that I get a period and, until I get the menopause, it'll still be that.
Physically, Beatrice has nearly finished her journey.
But there is more to being an adult than having an adult body.
The boys will soon be men, but that means accepting adult responsibility,
something 0lof is finding hard to do.
He's in trouble with his dad.
He's desperate to go to a party, but he's failed to finish his chores
and he's been grounded.
I've just been told I can't attend the party,
under my dad's decision.
He said I can't go.
We had asked him to do a certain thing and he had not done it.
More so than not doing the task, it was not accepting responsibility
for not doing it.
It's just a party and I...
This is just a small example of a much bigger part of development,
learning to use our reasoning to cope with complex situations.
(TEACHER) These are four digits, you know.
Young children tend to see life in black and white.
Pose them a problem that has no clear right or wrong answer,
and they'll have a very simplistic view.
Take this story, for example.
0nce upon a time, there was a man called George.
His wife was dying.
The chemist had a medicine that could save her life, but the medicine cost £1,000.
George didn't have £1,000 and, however hard he tried, he couldn't find the money.
So he stole the medicine.
(TEACHER) Do you think George should have done that?
No, 'cause he could have gone to the police. They could have arrested him.
And that's illegal.
(TEACHER) Illegal? What's illegal?
To steal.
He has got a right, but he has got a wrong to it.
What's right?
The right is that...
Well, he did ask nicely to get the medicine and the wrong is he stole it.
He shouldn't have done that.
- It's bad to steal. - Why is it bad to steal?
He can get into big trouble. You wouldn't like it if somebody stole from you.
Three years on, the certainty has all but gone and the response is dramatically different.
Was there no other way that he'd find the money?
- He tried everything. - He tried everything.
In that case, he should break into the lab and get the medicine for his wife.
Why do you think he should have done that?
Because a life is more important than stealing something.
It's a difficult thing. It's a moral subject.
Why is it difficult?
Because you're doing wrong and we've always been told not to steal things.
- But he's stealing. - Yes?
- So, it's a problem? - Yeah.
This ability to make complex moral judgements,
to see grey where before there was only black and white,
may well come from changes in the brain.
In childhood, the brain is constantly evolving,
as slowly an insulating coat grows around the nerves in the brain.
This helps information travel faster.
0ne theory is that at puberty the front part of the brain,
the area responsible for complex reasoning,
gets its coating.
It may be this that opens the door to mature judgement.
The rollercoaster ride is almost over.
0ur hormones have done their worst.
Girl has become woman, boy has become man.
And if the human body were to make a sound as it neared the end of this turbulent transition,
it would probably be a sigh of relief.
For us, there is also relief.
Having spent the last few years on the great ride of puberty,
we now regain at least the illusion of being in control.
0f course, there will be fine tuning,
and emotional turmoil will no doubt visit us throughout life.
Biologically, we are, at last, the finished article.
We are equipped for adulthood and, ready or not, we face the future.
I don't mind the physical changes at all.
They were meant to happen anyway.
I don't think I'd like to go round looking twelve for the rest of my life.
I don't think I'd be too happy about that.
I'm glad it's happened.
My biggest fear is taking responsibility for myself.
I can't rely on anybody else, once I've got full responsibility over myself.
It's my problem and I can't always rely on everybody else to take care of me.
I stick by my statement that I wish you woke up one morning and you were an adult.
I don't mind the growing, the growing in height,
but any other way is just a curse, the curse of puberty.