The Truth About Personality Horizon

I'm Michael Mosley.

As you can see, I was a blissfully happy child

but, although I still try to be cheerful,

this is now something of a mask.

I have a tendency to be a catastrophic thinker

and I think, "Oh, it's going to be terrible or I'm going to retire

"and I'm going to get some horrible disease or not have any money." Did that ever worry you?

No.

The truth is I'm now a bit of a pessimist.

I get stressed and I constantly fret about the future.

So, a couple of months ago, I set out to explore

the latest science of personality,

to see if it is possible to change.

Now, in many ways, I suspect this is going to be the hardest thing

I've ever attempted, but the rewards are also great.

I want to become a warmer, more open person.

I want to be happier and, from a purely selfish point of view,

I also want to be able to sleep better because I'm something

of a chronic insomniac and when I get stressed,

like I am frankly at the moment, I stop sleeping.

Is that too much to ask?

I've set myself a very ambitious task... To change my mind.

What I've been trying is something that requires no drugs,

no expensive therapy.

Instead, it involves a couple of unusual techniques

and, after seven weeks, I'm genuinely surprised

by what's happened.

That absolutely made my day, thank you. Brilliant!

Give it up for Michael, everyone!

So, can you really change key aspects of your personality?

And why might we want to?

This is Oxford, Ohio, a town in the American Mid-West.

It's not a particularly fun-looking town

but first impressions can be deceptive.

I'm starting here because the people in this place have revealed

the extent to which the mind can affect the body.

They've shown that what you think and how you think really matters.

It's a quiet - really quite unremarkable - little town,

and yet, back in 1975, it was the subject

of a really fascinating social experiment,

one which has been going on now for almost 40 years.

It started when a scientist from the local university

came up with an ambitious plan -

to recruit all the over 50s in the town for a study into ageing.

More than 1,000 of the locals duly signed up.

I've come to meet some of the members of that original group,

and they are a lively lot.

So, you guys kind of gather every morning or...?

You sound as though you're having a gas, I have to say.

-Every morning except Sunday.

-Who's the oldest person here?

-He's second, I'm 90.

-You're 90?

-He's 88.

88. You going to try and make 100?

I don't know. I tell you, when you get to be 90,

actually, you know, you live from day to day.

Ken, you took part in the original study which began in '75.

Do you remember taking part in it?

I vaguely remember taking part in it.

I mean, did you know how extraordinary it was

that they tried to recruit pretty well everybody in this town

at the time, and then they followed them

for whatever it is, 35 years now?

I don't think they've been following me though, have they?

Secretly!

In 1975, volunteers filled in questionnaires,

looking at things like health, jobs, family

and attitudes towards growing older.

Do you worry about the future?

No, no, I don't worry about the future.

I... What will come will come, and when it comes, it comes.

But, no, no. I don't worry about it.

If you just keep cyclically thinking bad thoughts, not good.

What do you see in people who are negative?

What do I see in them? I see an unhappy person.

I see a person who's more highly stressed than others.

To be stressed all your life, it would be...

wouldn't be a pleasant life.

Decades after the original questionnaires were filled in,

data from the Ohio study ended up at Yale University,

on the desk of Associate Professor Becca Levy.

So, what sort of questions did they ask?

One of the questions was, "How much do you agree or disagree

with the item "as you get older, you are less useful?""

OK, I would say that I disagree with it

because I'm sure that, as I'm getting older, I'm getting more useful.

Oh, good, very good.

Another question that was asked was, "As you get older,

"are things better, the same or worse than you thought they would be?"

-LAUGHS

-OK, I think I have no particular reason

for feeling negative about the future and yet I do.

What are you fearful of?

I don't know, just generally more anxious about stuff

but I don't know whether I'm just becoming more realistic

or whether the world really is a more frightening place

-than it once was.

-Yes.

It turned out that how you answered these particular questions

was a strong predictor of how long you were likely to live.

Mental attitude was far more important than anyone had imagined.

What we did is we tried to find the survival patterns of everybody

who was in the original study, so there's something called

the National Death Index in the United States,

and we found mortality information about all the original participants.

And when Becca went through the death records,

she found the same thing over and over again.

It was actually a survival advantage

on average of about seven and a half years

for those who had more positive beliefs about ageing.

So, something which actually increases life expectancy

by seven and a half years is quite a big deal, I think.

Were you excited when you discovered it?

Yes, so it was a bigger advantage than we had predicted

so that was really exciting to look at.

Ready?

Get happy!

One, two, three. Fine, right?

Becca's research has been backed by other work

looking into the power of optimism.

To put her results into context, if we could cure cancer tomorrow,

it would half as much, three to four years to life expectancy.

But what can you do if you're not naturally a positive, happy soul?

I keep on thinking that the worst is going to happen.

It doesn't happen but, in the meanwhile,

rather than engaging in the present and sort of being there,

chatting with my family, I'm sometimes staring off

into outer space, thinking about things

which will probably never occur.

I'm also still sleeping terribly and, so, if I could do something

that would make that different, then I would really love to do it.

Over the last few years,

I've looked at the evidence behind the science of how our bodies work.

I've tried a lot of different tests and procedures on myself.

Breathe in! Now I want to move on from the body to the mind,

to examine the science behind positive psychology.

And the first step is to find objective ways

to measure personality.

Our personalities are a complex interaction of character traits

that affect behaviour, emotions and ultimately the lives we lead.

And one of THE fundamental drivers is how optimistic

or pessimistic we are.

This is also one of the hottest new areas of scientific research.

But how on earth do you objectively measure it?

I am 5 ft 11, I'm 168 lbs

and my chest size is 42 inches.

Now these things are easy to measure

but what about aspects of personality?

Well, I've come here to Essex University,

where they're going to probe my brain

and apparently they can tell me

whether I am fundamentally optimistic or pessimistic.

Professor Elaine Fox is a neuroscientist

and one of the leading researchers in the science of optimism.

Now, ready? All I do is put in a small amount of gel

and then you'll feel it cold.

We know that some people's brains tune in very much

to negative information and others tune in

to positive information, and what we're hoping to do,

we're measuring the electrical activity in your brain

and we're really just going to try and probe

and see whether your brain naturally tunes in

to either positive stuff or negative stuff.

I am, I must admit, phenomenally interested

-to see what you discover because...

-Yes, it'll be interesting, yeah.

I would suspect that I have a bias towards the negative.

Do you think so? Yes.

It may turn out that I'm a rip-roaring optimist.

Well, it absolutely might, yes, exactly.

It's funny because I have these conversations with my wife

quite frequently because she has a... I think, a kind of naturally

sunny disposition, and she finds it quite frustrating.

You know, she keeps on saying, "These things won't happen."

-No, exactly.

-"Why do you keep thinking about them?

"Why do you keep on talking and planning about things,

"which the odds on them ever, ever happening

"are just fantastically low?

"Why don't you just wait and see what happens?"

It's a disaster, the kids will all end up in jail.

Embarrassingly, I can't even stop worrying

while they're setting this up.

Oh dear, there's a flashing light there. It's not good.

It's not my bloody job, I know that.

My eye keeps on being drawn to it and I keep on going,

"Is that important?"

Don't worry about the flashing light.

I know, it's nothing to do with me but I can't quite stop myself.

The first part of the test involves measuring levels

of electrical activity on the two sides of my brain while I'm resting.

Surprisingly enough, studies have shown

that people who are prone to high levels of pessimism,

neuroticism and anxiety tend to have greater activity

on the right side of their frontal cortex than the left.

This is known as cerebral asymmetry.

We know it happens, we don't know why.

Now for something more active.

Elaine's asked me to press a button

when I see dots flashing up behind faces on the screen.

At the moment, I'm just in a kind of a completely zoned-out territory.

I have no idea.

That was a cock-up, yeah.

I didn't realise while I was doing it

that the whole point is to test unconscious biases.

They wanted to see if my response time was influenced

by whether the dots appeared behind angry or behind happy faces.

Did that kind of go as you'd planned?

Yes, it did. There's the data.

Ay-ay-ay!

God, this is not a good look, is it?

-KNOCKS

-Hello, there!

-Hi, Michael.

A couple of hours later, and my results are ready.

The computer measured the speed that you pressed the button

and sometimes there was an angry face on the left hand side,

say, sometimes a happy face on the right hand side,

so you can see that's how quickly you responded

when the target appeared near the angry faces.

It's extraordinary. My reaction times are much faster...

-Much faster, as you see.

-..with the angry faces.

Exactly, so when the little probes appeared where the angry faces were,

you were actually much, much faster, so...

That is, OK, that is extraordinary.

I had absolutely no idea that was going on at all.

Exactly, it's a little probe into your mind showing us

your brain is just slightly faster because you were already there.

Your attention has gone to the angry face immediately,

so when you react, because you're already there,

you're a little bit faster.

But Elaine has found something else which is a bit more unsettling.

The first part of the test, where they measured my brain activity

at rest, revealed I have nearly three times more activity

in the right frontal areas than the left.

This suggests a brain that is even more tuned to the dark side

than I thought.

I would have been surprised if your machine had decided

that I was a raging optimist, because that isn't true.

But I'm also not clinically depressed either.

That's what it shows.

I incurred a bit on the negative side, but not extraordinarily.

I think that's exactly... It's on the negative side of the spectrum.

I'm now wondering if Elaine is simply being diplomatic,

and if my results are rather worse than she's suggesting,

or is that just paranoia?

So, that test has shown what I guess I've always believed,

that I have a fundamentally negative filter and that makes me

prone to pessimism, anxiety and also sometimes neuroticism.

It colours my relationships and also affects how I react to the world.

# Sometimes I go out by myself... #

A brain that is hyper-aware of things that can go wrong leads

to increased stress and anxiety, and it's more than just a state of mind.

It's powerfully connected to how your body responds.

I've come to this karaoke bar to sing - badly -

in front of 100 strangers.

I'm here to demonstrate what happens to your body

when you allow negative thoughts to dominate your mind.

# ... over, Valerie. #

# So now you're back from Outer Space

# I just walked in here to find you here

# With that sad look upon your face... #

My body is really screaming at me,

this is a really, really bad idea because my pulse is running

at around 120, my mouth is dry and I've got a faint tremor.

Areas of my brain that deal with fear and threat have kicked in.

These evolved to ensure survival

but today it's not a sabre-toothed tiger that's terrifying me,

it's just a little sing-along.

I mean, it's sort of odd

because you'd imagine somebody who makes a living out of

appearing in front of a camera would feel quite comfortable, but I don't,

I don't feel remotely comfortable about doing anything like this

and I can see the whites of everyone's eyes

and that fills me with horror.

Will you please welcome the next singer?

Mr Michael Mosley!

# First I was afraid, I was petrified

# Kept thinking I could never live without you by my side... #

The first bit of the song is OK because I just have to shout

but when the music kicks in, I'm stuffed.

Before I came on, I was thinking, what happens if I freeze?

And that thought became self-fulfilling.

I've totally shut down.

Now this is obviously a highly unusual situation

but it certainly demonstrates the power of negative thoughts

to influence human physiology.

After the pleasures of karaoke,

I'm in Boston, Massachusetts, where engineers have invented

a discreet way of measuring that most elusive of things -

our emotions.

It's a device created by Professor Ros Picard,

who runs the media lab here,

and it's something you can wear day and night.

So, Ros, I've got these wrist bands.

What exactly are they doing?

You need to think about this sort of, as like a new kind of

wearable microscope that lets you look inside your body

and see some things that previously you couldn't, couldn't see.

How interesting! So, essentially, you're using these

to read emotions that people

cannot necessarily express or don't even know they're experiencing?

That's right, and sometimes they're full of surprises.

Oh, you're tantalising me. You're doing very well.

OK, are you wearing a pair or is that just a big, snazzy watch?

Yeah, this is just a prototype of a future version that's coming out.

OK, great.

The wrist bands can monitor someone's emotional state

by detecting minute changes in the electrical conductivity

and temperature of the skin.

These are driven by the so-called autonomic nervous system.

And I'm being monitored even while we talk.

Why not just rely on people filling in questionnaires?

Why do you need technology?

Oh, goodness! People just will say the darndest things

on questionnaires, right?

They'll think that they're happy, "Of course I'm happy," you know,

and, finally, you know, 20 samples later,

they realise they're miserable, all right?

We find that the body often tells you

there's a change in your state well before your mind recognises

that change, so even if you're trying really hard to be truthful

on a questionnaire, usually your awareness of what's going on

lags quite a bit behind.

OK, you've been wearing these wrist bands the whole time

we've been interacting, and now I'll take them off

and we're going to take a look at your data.

OK, and you can do it that fast?

Oh, yes, it's very quick.

It's not often you get to see a chat going on

and also see at the same time what's going on inside you.

The readings are higher when I'm excited or anxious,

and lower when I'm calm.

It's what Ros calls my arousal level.

All right, what we have here is four signals.

The red is your right side, the blue is your left side.

This is my left side and my right side.

So, first of all, we're seeing that your baseline arousal

is higher than mine during this social interaction.

So, the wrist bands show I'm more aroused than Ros

but am I stressed or just excited?

As with the brain test I did earlier,

the thing Ros is interested in is, which side of my body

is showing more activity?

There's clearly higher response on my right wrist than my left,

and research suggests this can be linked to my amygdala,

a part of the brain which evolved to deal with fear and threat.

Now, most arousing experiences activate both of them

but certain kinds of experiences, like social phobia,

or threat-type situations, we would expect for a right handed person,

the right one to be activated more.

How interesting! So, that is absolutely compatible with somebody

who feels mildly socially phobic and is an uncomfortable situation?

That is what we would expect.

Wow! And that is quite tiring,

I imagine, looking at that to sustain that sort of level of peak?

It's work. Being around people can be hard work.

Thank you, it's been absolutely... It has been genuinely fascinating. Thank you.

# I'd rather go on the road

# Nah, nah, nah, nah, nah, nah

# I'd rather go on the road

# Nah, nah, nah, nah, nah, nah

# I'd rather go on the road

# Nah, nah, nah, nah, nah, nah... #

Ros's emotional microscope has certainly exposed

the sort of feelings that most of us try to hide.

And I was really surprised because I thought I would be the cool one

and she would be the nervous one,

but actually it turned out to be the absolute other way round.

I didn't actually feel nervous

but clearly my system was firing on all cylinders.

And these levels of heightened anxious arousal are something

I want to change, not least because it has probably contributed

to making me a chronic insomniac for the past 20 years.

OK, oh, dear.

I've had a spectacularly bad run of nights recently.

Up at about sort of 4 o'clock last night.

You can probably see the bags under the eyes.

And, um, let's see how tonight goes.

I hope it's better than last night.

Good night!

Yeah, it's 4:30am and I'm wide awake.

Lots of thoughts racing through my head

and so I thought I'd get up and sit around a bit.

I'm going to try two different techniques, which have been shown

to reduce negativity and stress.

To learn more about the first technique,

I've come back to Essex University.

Professor Fox's brain test measured my levels of pessimism

but being a very positive person herself, she's convinced that

not only can she help me, but we'll see changes in my brain.

She introduces me to cognitive bias modification - CBM.

Basically, it's very simple.

If you just press 'start' there, you'll see an array of faces.

Now, your task is simply to click on the happy face.

-OK, OK, happy.

-Yeah, and then just keep going, basically.

Blimey, it's quite difficult to find them, isn't it?

Yeah, so just find a happy face.

There have been many studies of CBM involving several thousand people.

The idea is you reduce your unconscious negative bias

by training yourself to seek out the positive.

OK, whoo!

No, he's not down there.

Let's go across down there.

I simply have to spot the smiley faces.

How hard can that be?

You think when you look at it, it's going to be dead easy but...

That's right, it's more difficult than you imagine

and it shows us how distracting the negative faces can be.

I do actually like the smiley faces, you know,

and yet I'm obviously drawn to the dark side.

Yes.

Your brain has obviously got into a habit of looking

on the negative side of things, so what we're trying to do really

with this cognitive bias modification is to really try to break that habit.

The majority of people who have been studied

showed a significant reduction in their negative bias.

I have to say if it works, then the beauty of this is

you can absolutely see you can just do it on your computer at home.

Absolutely, and that's the idea.

What we're hoping eventually is that people can almost use this

as a little top-up. It's like, you know, if you feel

you're in a particular negative mood, you can do ten minutes of this

and you know it can kind of just boost that bias.

OK, I remain sceptical but I will certainly,

I will certainly give it a go.

Elaine set it up so I can do this at home three times a week.

Where is it? Sometimes it's really, really annoying,

I just can't find them. Aha! OK.

Yeah, I'm on a roll.

I'm just kind of letting my unconscious do the work

and, ideally, I just kind of don't even think about it.

I have absolutely no idea whether this is helping

but I'm not convinced I'm actually getting any faster.

Where are you, where are you? Ah!

It looks incredibly simple.

But there is evidence it will combat anxiety, though not depression.

# Suddenly, I'm hit

# It's the starkness of the dawn

# And my friends are gone

# And my friends won't come

# So, show me where you fit... #

One of the things that undoubtedly adds to my feelings of anxiety

is my tendency towards self-absorption.

I'm rarely enjoying the moment, being in the present.

Instead, I'm off worrying about the past and stressing about the future.

This is a very common problem and it's making a lot of us miserable.

So, I'm off to find out more about a second technique that may help.

I feel like I've got caught in the sort of negative rut

of ruminating, and I've spent a lot of time now visiting labs,

learning about the science of the brain but, oddly enough,

where I'm going now in search of solutions is to visit a former monk.

Followers of different religions have practised meditation

for thousands of years.

There are, of course, many different ways of doing meditation,

including secular versions.

Tonight's teacher, Andy Puddicombe, was once a Buddhist monk.

He now teaches a modern take on an old idea.

Now, take a moment to think who here struggles with sleep.

Quite a few of you, right?

When you've gone to bed and you really need to sleep, OK,

what's the temptation?

To try a little bit harder, right?

And then you start to get a little bit tense

because you're not falling asleep, so you try even harder,

and then you realise that you're trying too hard to get to sleep

so you try not to try to get to sleep, so there's a time

and a place for stepping back and saying, you know what?

It's not about effort. Meditation's the same.

You can't force a state of relaxation.

This is a treat, it's not a chore, OK?

This is YOU taking ten minutes out of your day to do nothing,

nothing at all.

It's such a rare opportunity.

Ten minutes out of my day is not a huge commitment.

So, I'm certainly interested enough to want to find out more.

I'm a chronic insomniac, I wake at 3 in the morning

and I have loads of thoughts racing through my head.

I have spent 15 years looking at sleep.

I have made, you know, at least three programmes on sleep.

I know pretty much everything there is to know about sleep

but it doesn't make any difference.

The science that's coming out is showing that actually even ten,

15, 20 minutes a day, that's enough to make not only

a psychological difference but a physiological difference as well.

Over the past 20 years,

there have been lots of studies of varying quality into the benefits

of meditation, which have produced rather conflicting results.

But, recently, there have been more rigorous studies,

involving brain scanners and these have allowed scientists

to see what's happening inside the meditating brain.

There is evidence of changes in the brains of long-term meditators.

Even novices doing it for just eight weeks showed some differences.

In one study, there was increased grey matter in areas

involved in emotional regulation,

and increased activity in the left pre-frontal cortex

that deals with positive emotions.

It's early days, but the evidence is certainly mounting

that regular meditation can lead to physiological changes.

If it is THAT easy, why haven't more people done it?

Yeah. And this is the thing. I wouldn't say it's easy.

I'd say the idea is easy, OK?

The application, like anything, it's like losing weight,

going to the gym.

We still need to actually do it

and we have to do it on a daily basis to see the results.

There is nobody I know who wouldn't benefit from being more present,

having a greater sense of calm, a greater sense of clarity,

and, ultimately, a greater sense of contentment in life.

-Is six to eight weeks enough?

-It is enough, yeah.

You could actually see changes possibly in my brain pattern

-in six to eight weeks?

-Absolutely.

So, it's time to give it a go myself.

I'm going to try and calm my brain down by simply focusing

on my breathing and being less distracted by my negative thoughts.

Oh! And I have to try and stay awake.

I'd like you to begin by just noticing

the weight of the body on the chair

and just starting at the top of the head,

I'd like you to just gently scan down through the body,

just noticing which parts of the body feel relaxed

and which parts feel perhaps a little tense or tight in some way.

Then, if thoughts arise, that's perfectly normal.

Allow thoughts to come and go.

As soon as you realise the mind's being distracted,

just gently bring the attention back again.

And, in your own time, when you're ready...

You can just gently open the eyes again.

OK, so how many of you feel better

than you did ten minutes ago?

OK. It's amazing.

There's a tangible thing happening here.

We train the mind, we will be more present,

our mind will wander less, we'll get less stressed

and we're less likely to go down those routes, those habitual paths

of stress, of anxiety, of sadness, whatever your thing may be.

That was good actually, because I wondered

whether I would be able to get into any sort of a state,

and I feel a little bit heavy-limbed

but I also feel perhaps a little bit

more relaxed than when I went in,

and I veer wildly between optimism

and pessimism, so that part of me thinks that I'm going to manage

to do this and part of me thinks it's simply going to be too hard.

But, at the moment, the optimist is winning out.

To give this a decent chance of working, I have to commit

to doing it every day, building up from ten to 20 minutes.

And I'm going to combine it with cognitive bias modification.

In seven weeks, I'll get my brain re-tested

to see if I've really managed to change my mind.

OK.

But, while I do that, there's a deeper question I'm grappling with.

Where does a tendency towards being optimistic or pessimistic,

calm or anxious, come from?

I was a happy child, carefree even.

So, yeah, there I am.

I'm not... Don't know if I've ever seen this.

It doesn't ring a bell.

OK, so this is definitely the Philippines because I was there

when I was about, between the age of two and five.

And there's my mother, right.

She looks ludicrously young, my mother.

I asked her about how she remembered ME from childhood

and she said that I was uncomplicated,

that I got on with things, I seemed to be open and friendly and, looking

at this footage, it certainly looks like I had a happy childhood.

Just on a swing, rocking to and fro.

There are lots of pictures of us here. There aren't really any pictures of my father here.

There are pictures of my mother, but my father was always working.

He was never really around in our childhood - very little.

In terms of personality, my father was a jovial extrovert,

while my mother was a bit more uncertain and reserved.

Like everyone, I came to be who I am today through some combination

of the genes I inherited and the events I've experienced

throughout my life.

Oh, dear!

I feel I am so utterly different to what I must have been like

at the age of three or so.

I look so cheerful.

There are a lot of rather big theories

about how personality comes about

but I'm in search of cutting edge science.

I'm starting at St Thomas's Hospital in London

where, for many years, a research unit has been analysing

and probing a very special group of people - twins.

Twins are one of nature's wonders.

Identical twins share the same DNA.

They often dress the same,

look the same,

laugh at the same jokes.

And so, hundreds of twins have been scrutinised to understand

the subtle interplay of nature and nurture.

I just think it's absolutely wonderful, I must admit,

being surrounded by identical twins.

Professor Tim Spector has studied twins for over 20 years.

The first and most obvious question I want to ask

is, when it comes to your personality,

how much is inherited directly from your parents?

Twin studies have told us

that personality has a heritable component, and they tell us

that generally 40 to 50% of personality,

of differences between us in personality,

are due to genetic factors and the rest, either random,

or due to environment.

Tim spent the early years of his career investigating

what made identical twins uncannily similar.

Then he changed the focus of his research,

began to wonder why identical twins are not always identical.

Three years ago, I just changed my mind.

Because twins don't get the same disease,

don't die of the same things, it can't just be genes alone

and let's look at the differences between identical twins

and that could probably tell us MORE than why they're similar.

That's great about being a scientist rather than a politician - changing your mind.

You can change your mind and no-one stops voting for you, that's right.

Tim wanted to find out how people who are born with the same DNA

can end up very different.

I've come to meet a particularly unusual pair of identical twins,

Debbie and Trudi.

Oh! LAUGHS

Oh, dear! I've obviously got dirty fingers there.

I'm wiping them off. Oh, what's she found?

Like all identical twins, Debbie and Trudi were born with the same DNA.

Have you noticed that your trousers are a different colour?

You've got brown trousers on.

No, you're the one in the yellow coat with the brown trousers.

I've got blue trousers on with a white coat. That's you!

-No. Oh, yes, that's me.

-Yes, that's definitely you, look.

They shared the same environment for the first 20 years

of their lives, went to the same schools, had the same friends.

-THEY LAUGH

-I think that's brilliant.

-You just couldn't coordinate, could you, really?

-No, not really.

We were cute, weren't we?

You are cute, honestly.

THEY LAUGH

You might expect them, like most other sets of identical twins,

to have similar personalities.

You can see we're just, you know, happy. Happy, happy, happy.

-You look jolly children.

-We were.

And that's possibly because we never felt that we were on our own.

We only ever needed each other.

Well, let's put it this way, anybody throughout our lives who

got in the way of that relationship didn't last.

Scary!

The twins are still extremely close and spookily similar in many

respects, but these days, there is a critical difference.

Unlike her twin, Debbie has developed clinical depression.

If I had met you at 16, would you have been able to predict

-which of you would have become depressed?

-No.

-No.

-Would you have said either of you would become depressed?

-No.

-No.

No.

Today, Debbie and Trudi have come to St Thomas's Hospital for tests.

They're part of a group of what is known as discordant twins

that Tim is studying.

How can twins who share the same DNA

and the same life experiences end up being so different?

Tim thought it must be because something had happened

to their DNA, so he began looking for differences.

Because, surprising though it may seem, our genes aren't fixed.

They can change.

As we go through life, all our genes are changing constantly.

As we age, some of them are being switched on, some of them

are being switched off. And we think that these are actually

reflecting things like our environment and the lives we've led.

They're like a marker of our lifelines in a way.

This process is known as epigenetics, and I think it is one

of the most exciting developments in modern medicine.

Life events can change the activity of our genes,

so it seems at some point in Debbie's adult life, changes

to genes in her brain made her more vulnerable to bouts of depression.

So with somebody like Debbie and with Trudi,

did you actually find differences in their DNA?

We did, and when we looked at a larger

group of 30 of our twins, where one was depressed and one wasn't,

we saw certain genes coming up time and time again.

We identified about five or six that were clearly different,

particularly in areas like the hippocampus, which we know are very

important in anxiety and depression, where a lot of the emotions are.

I have to say, I find it mind-boggling.

Well, that's the exciting bit of science,

and the fact that we're only able to do this in the last

couple of years because of the amazing advance in technology.

We all know that stressful, emotional events, like a death or

a separation, can trigger depression, but what scientists now

believe is they can also change the behaviour of our genes.

This raises the enticing possibility that

if your genes can be switched one way, then maybe, just maybe,

they can also be switched back the other way.

Well, we used to say we can't change our genes, but we now know

there are these many mechanisms that can switch them on and off,

and suddenly we're regaining control, if you like, of our genes.

I like the idea of regaining control,

and that encourages me to keep going at mindfulness and CBM.

It's quite charming, really, because you just kind of

have grown to know them a little bit, these faces.

My seven weeks are almost up,

and I've got one more neuroscientist to meet.

'An inspiring guy who's been working on the puzzle of genes and personality for a decade.

'Professor Michael Meaney has been able to do pioneering work

'thanks to a unique collection.'

Wow! This is quite a lot of brains.

-It's impressive, isn't it?

-It is, yeah.

This is the Quebec Brain Bank.

It takes an enormous amount of organisation,

and it was something that started with just an idea, right, of could we collect brains?

Each of these 3,000 brains once contained a unique personality,

a unique set of memories and experiences, and each

is accompanied by a biographical record about the individual.

This is the great virtue of this particular bank,

is they use a process referred to as forensic phenotyping, so what

they're doing in fact is to go back and interview family members

and to find out as much detail as possible about the developmental

history of the individuals as well as their level of pathology.

Michael set out to identify the precise areas in the brain

where anxiety is controlled, but with billions of cells

in an average brain, it would have been an impossible task.

So he turned to a group of small, furry mothers to help - rats.

He started by looking at the long-term effect on baby rats

of good or bad maternal care.

What does maternal love or affection look like in a rat, then?

It's essentially licking, we think. It's tactile stimulation.

It's what you do when you hold an infant, when you caress an infant.

It's physical contact between the mother and the offspring.

What surprised us is the variation, that there are really some

mothers who lick two, three times as frequently as do other mothers.

-So there you see.

-Ah, OK, little baby rats.

Little baby rats. And what the mother's doing in the course of her nursing of the offspring

is to lick individual pups, which you can see right there.

And it turns out that the pups that are reared by mothers who lick

more frequently grow up to develop more modest responses to stress.

Michael found that the amount a baby rat was licked influenced

the activity of the gene that protects the rat

later in life against stress and anxiety.

This was a clear epigenetic effect

and was similar to what happened to the twins.

Something in the baby rat's brain had been modified by its life

experience, but did this change also affect the next generation?

Have you reared them through generations to see

if the pups who were the offspring of low-licking mothers

themselves become low-licking mothers?

Yes, the great female rat nightmare comes true.

They become their mothers.

And so really what you have is a situation in which you can

-transmit these differences across multiple generations.

-Right.

I must admit, I'd never thought about neurotic, anxious rats before.

-You can start now!

-MICHAEL LAUGHS

And what's striking is the changes in the rats' genes

brought on by maternal care were detectable in their brains.

What you're looking at here are sections of a rat brain,

and in particular what we're interested in is the hippocampus.

And the hippocampus is associated with stress, emotion and memory?

Exactly, all three.

So we now have to find the molecules within the hippocampus that

control the stress response, and we find a particular molecule

known as the glucocorticoid receptor.

It turns out that the number of these crucial receptors they found

in a rat's brain could be predicted by their mother's behaviour.

Better mothering led to more receptors.

And what you find then is that the mothers who licked their offspring

more, produce offspring who then show more modest response to stress.

-How very satisfying. That must have been rather exciting...

-It was, it was.

I find this work stunning and ever so slightly disturbing.

A clear link between the amount of maternal affection a baby rat

receives with changes in its genes and in the anatomy of its brain.

But is this true of humans?

This is where Michael's collection of human brains proved invaluable.

He studied the brains of people who'd suffered from extreme anxiety,

and he found the same changes as in the rats.

By looking at their childhood records, he could also tell

if they had reported receiving good or bad maternal care.

Maternal care is actually a major influence,

and perhaps the pre-eminent influence in defining how we respond

to stress. So it's not only true for a rat, it's true of our own species.

So if I respond badly to stress events,

and we all have stress events in our lives, it could be

because I have low levels of glucocorticoid in my brain?

It could very well be.

So the reason I'm a terrible insomniac could be,

I could blame it on my mother not licking me enough?

-You can try.

-MICHAEL LAUGHS

When you put the research on twins together with Michael's work,

it adds up to a really powerful new way of being able to study

the forces that shape our personality.

Personality is not just something we are born with,

but something that is subtly shaped and modified throughout our lives.

And that thought that we are quite flexible makes me feel cheerful.

Maybe the meditation and the CBM are starting to work after all.

-VOICE ON TAPE:

-'Meditation benefits those around you as well.'

My wife, Clare, certainly seems to think something's happened.

Given that you've been under quite a lot of stress recently,

actually, you seem to have been sleeping better.

And you've certainly not...

You've dealt with the stress, I think, amazingly calmly.

Whether that's meditation, I don't know, but I think...

..I think it's helped. I do think it's helped.

What do you think?

SHE LAUGHS Hiding!

It's results day and I'm feeling uncharacteristically optimistic.

It's been a really stressful few weeks

and I have been working a great deal, but I've been sleeping better

than I have for ten years and I'm feeling quite good.

But will the machines agree?

'Although I feel better, I also want some concrete proof.

'Have I actually changed my brain?'

Hello, Michael, welcome back to the lab. How are you?

I'm going to stay in this position, I think.

Yes, we're gunging you up again.

So as well as the smiley faces,

I've also been doing mindfulness meditation.

I have to say, that is more challenging, just sitting there,

-not doing anything, sort of just listening to your breath.

-Yes.

Certainly, when it came to the kind of 20 minutes, I would

find myself sneaking a look at my watch after about 16 minutes.

Just doing it was so not what I normally spend my life doing.

OK, do you feel any more positive?

I think I do, actually. I'm feeling... I feel more cheerful.

First, the team measure my cerebral asymmetry while I'm resting.

Seven weeks ago, I had nearly three times more activity

in my right frontal cortex than my left one,

which was a striking indicator of pessimism.

Next, I'm repeating the test with the faces, to see

if my reaction times have changed.

Seven weeks ago I was much quicker to hit the button

when an angry face appeared.

Will that still be true?

I'm vaguely conscious there are faces appearing, but...

..couldn't tell you.

It's actually completely impossible to tell how you're doing on this.

So, have seven weeks of mental training made any measurable difference to my brain?

-Great, moment of truth, then.

-Yes, exactly, yes.

OK, well, we've got the results here, and as you can see here, the blue...

'First, I get the results for my reaction times to the face test.'

Seven weeks ago, my reactions to the happy faces were much slower

than the angry ones, but this has now reversed.

I'm much quicker to react to happy faces.

This suggests I may be noticing the positive more in my everyday life.

And now you can see this has flipped completely.

-You're now faster when there was a happy face, compared to...

-So it really has made a difference.

I'm amazed. I'm just impressed that it comes up with the results.

-Yes, and again...

-You're measuring things which are unbelievably subtle and speedy, aren't they?

Well, they really are, and if we look at the reaction times,

it's milliseconds, so we're not talking about huge differences.

-It's not seconds, it's milliseconds.

-Yeah, thousands of.

So you consciously wouldn't really be aware of that,

but actually, in brain time, that's actually quite meaningful.

'Mine is just one result but it fits in with studies which

'suggest that this technique can reduce negative bias and anxiety.

'And the changes in my cerebral asymmetry are also fascinating.'

The activity in my right frontal cortex has significantly reduced,

which suggests a shift towards a positive mental state.

And my suspicion is, even though we can't really separate them,

my suspicion would be that this is more driven by the mindfulness

meditation, because there's a lot of evidence showing that with

these measures, mindfulness is very powerful and very effective.

So, initially, you were showing a very typical pattern of pessimist.

Now you're showing a much more typical pattern of an optimist,

so it looks like your brain has shifted in a slightly more optimistic direction.

-So you really can change your mind?

-Yes, you can, and it's not easy.

'I am pleased, but the real challenge is to keep on doing it.'

Fantastic. That's absolutely made my day. Thank you, brilliant.

I shall go off and celebrate now.

I'm absolutely delighted and also I'm frankly astonished

that in just seven weeks you can see that much change.

I set out to see if it's possible to change my mind,

and I think I may well have done it.

I am absolutely thrilled.

MUSIC: "Bad Moon Rising" by Creedence Clearwater Revival

I started out wanting to be less anxious and more optimistic.

I discovered that life events can lead to deep, long-lasting

and measurable changes in our brains.

# I see the bad moon a-rising... #

But I've also discovered that our personalities are more

malleable than many of us think.

Negative thoughts can dominate your life.

But I certainly have found something to be cheerful about again.

# I see the bad moon a-rising

# I see trouble on the way

# I see earthquakes and lightnin'

# I see bad times today

# But don't go around tonight

# Well, it's bound to take your life

# There's a bad moon on the rise. #

Subtitles by Red Bee Media Ltd