The Infinite Monkey Cage - Teenage Brain

Episode Date: January 29, 2018

The Teenage BrainBrian Cox and Robin Ince are joined by impressionist Rory Bremner, Professor of Cognitive Neuroscience at UCL Sarah-Jayne Blakemore and Professor of Zoology at Manchester University Matthew Cobb to look at the working of the teenage brain, and why teenagers are so, well, teenagery. Stomping off to your bedroom, being embarrassed by your parents, wanting to fit in with your peers and a love of risky behaviour are all well known traits associated with our teenage years, exasperating parents through the ages. But new research into dynamic changes going on in the brain during these key years has revealed that it's not just hormones that are responsible for these behaviours. Could a better understanding of what is going on during these formative years not only help teenagers themselves, but inform our education system and even help prevent many of the mental health problems that often begin during adolescence?

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This is the BBC. Hello, I'm Robin Ince. And I'm Brian Cox. Today we ask, was Brian's pop career just a phase he was going through due to the changing structures of his teenage brain before he entered the adulthood of being a particle physicist? And why did Robin remain trapped in the perpetual

adolescence of being a stand-up comedian? Shut up, Brian. I'm not... You're such an idiot. Anyway, so... And in fact, anyway, I am now a serious Radio 4 broadcaster, somewhere between Melvin Bragg and Nicholas Parsons. Which is how I got the job. So...

Today, we discussed the science of teenagers. What physiological changes occur in the brain during the teenage years? Is there an evolutionary explanation for them? Do these changes occur in other animals? And why didn't these changes reach completion in robinins? William, you are being so extra. I have no idea what that means, but I asked some teenagers.

Extra was very much the word for the moment. Now, watch me radio for this intro, right, if you don't think I've got it. Today, we explore the teenage brain. We have three eminent grown-ups, and they are... I'm Professor Matthew Cork from the University of Manchester, and the strangest thing that I did as an adolescent was to think that I could write poetry.

I'm afraid I think I actually sent a whole bundle of them off to Ted Hughes, who didn't reply, which is probably the best thing. I'm Professor Sarah-Jane Blakemore from UCL. I'm a cognitive neuroscientist. And yeah, I'm not sure it's the strangest thing, but maybe one of the more risky things I did as a teenager was to hitchhike around the south of France with my friend Kath, occasionally ending up in lorries or vans, one time in the boot of someone's car, just to get to the beach. I'm Rory Bremner, I'm a fellow of King's College,

and I have an honorary doctorate in advanced mimicry from Heriot-Watt University. And... And the strangest thing i did as a teenager the riskiest thing i did as a teenager was to run through a field of wheat oh sorry and this is our panel before we continue by the way we should make it quite clear that in no way does this show recommend you climb in the boot of anyone's car. So, Rory, first, what, for you,

defines what you think of as a teenager? Ooh, uh, moody, insecure, impulsive, impressionable, sorry, that's Donald Trump, isn't it? No, I would say, well, actually, a lot of those still apply um emotional hormonal anxious desperate to fit in i think all of those are part of teenage years so they certainly were for me so that is that that for you is the archetype or what our presumption that we would make i i think that's pretty true that kind of that straight you know that the mixture of attempting to be gregarious but also at the same time that, you know, desire for loneliness,

staying in your room and that. Well, I mean, there are so many contradictions. Quentin Criss got it right about this, as about so many other things. He said, the thing about teenagers is they have the same problem, how to rebel and conform at the same time. And they manage this by defying their parents and copying each other so there's that contradiction of rebelling and conforming but also to be an individual but also peer pressure which is the biggest thing i mean it was particularly my school because in fact a lot of the children

went on to become members of the house of lords but i can remember that the pressure took all the lads you remember as a teenager i used to so look up to the lads because they seemed so cool and so dangerous, and I wanted to be one of them. And then the other day, I actually met one of the people who I thought was the biggest lad in the school, and he'd just left the army and become an estate agent. Yeah, I saw that. I looked up someone the other day who was the most rebellious kid,

and he works for British American Tobacco, so there we are. Sarah, I suppose some of those descriptions of teenagers are almost cliched but in a scientific sense is there a fundamental difference between teenager and an adult? Yes there is. There's a lot of evidence that teenagers go through a period of their life where they're more self-conscious and more moody. That's probably the hormones. But also things like risk-taking seems to be heightened during the teenage years and adolescence. That's in adolescent humans

and in non-human species of animals as well, like rats and mice go through a period of heightened risk-taking when they go through their adolescence. And as Rory mentioned, peer influence, that seems go through their adolescence and as Rory mentioned peer influence that seems to peak in in adolescence so adolescents are more influenced by their friends than children are or adults are and you mentioned the hormones there that tends to be the sort of the idea that everybody puts forward that hormonal changes in your body and that makes you more moody but is there more than that are there physiological differences yeah so when i was an undergraduate 25 years ago that's what i was taught i was taught

that teenage behavior is all down to hormones changes at hormone of sex hormones at puberty and changes from going to a little primary school to a big secondary school with lots of new faces and lots of new people but that was because 25 years, we had no idea what's going on in the brains of teenagers. We didn't have the ability to look inside the living human brain, to look at how it changes across the lifespan. We now do. We use MRI scanning to scan the living human brain of all ages. And for the last 20 years,

lots of different labs around the world have been doing that. And we now have a really rich picture of how the teenage brain develops and it's and the idea that uh the brain stops developing in childhood which is another thing that i learned when i was an undergraduate is completely wrong and in fact the human brain continues to develop right throughout childhood right throughout adolescence and even into the early 20s because it's about adult size, eight or nine years old, isn't it? So it's not size that changes, it's the, what is it, the construction, the architecture of the brain itself. Yes, so the volume of the brain, the size of the brain,

reaches adult levels by about age eight or nine. It's not that that changes, it's the structure of the brain, how its composition, how much grey how it's its composition how much gray matter it has and how much white matter it has and also how it functions how how it becomes activated when you do a certain task like for example when you take a risk or you make a decision or you inhibit an inappropriate response matthew do we see a period of adolescence in in all animals i mean we always joke about the fact that you do some work on maggots. Is there a kind of a grumpy teenage fly that goes into that excrement

just deliberately to then leave footprints of poo on your cake as an act of rebellion? Or do we see a cut-off point of those that don't have adolescence experience? I think basically what we find is that in mammals in particular then there is a period of change, hormonal change, to do with the passage into adulthood and that is associated, as Sarah-Jane

says, with lots of risk-taking and changes in particular, when we say risk-taking we're not talking about them trying to jump off cliffs or anything. Rats and mice will be much more interested in novel objects. So if you're a rat or a mouse, it's a really dangerous thing. Something new in your cage is worrying, so you won't go towards it.

And what happens is that the rats and mice will show a much shorter latency to respond to that. They'll start going out and sniffing it and be interested in it. So you can get something which we interpret as risk-taking, but is in fact basically just a lowering of the threshold at which they're ready to move. Normally an adult rat will take some time and be very, very wary, but a juvenile adolescent rat will be much more quick to respond. What's the time scale there for a rat? How old are you if you want to be a teenage rat? Rats go through about 30 days of adolescence

when they're about 30 days old. Right. So 30 days of adolescence. 30 days of adolescence. And mice the same. And there was a nice study published a couple of years ago showing that adolescent mice drink more alcohol when they're with other adolescent mice.

And that's not true for adult mice. Adult mice drink the same amount of alcohol whether they're on their own or with their cage mates. There are some outtakes from bagpuss, which really change. They are not marvellous and mechanical. But actually, doesn't it look like, as you said before, the perfect storm, really, because you've got all the hormones,

but at the same time, as we now know, all this activity that's happening in the brain, it's like a cosmic trick, how teenagers, when they're vulnerable, are exposed to all of this at the same time. Yes, I mean, it is. It's like a perfect storm. They're going through changes both physically with their sex hormones

and their bodies change. That means that society treats them differently. You might know a lot more about that, Matthew, because it's true for non-human species too. And also their brains are undergoing huge amounts of change and their social environment is changing. Their social environment becomes really chaotic and unstable, where people are trying to work out where they are in social hierarchies.

All these changes put together mean that adolescence is quite a vulnerable time. It's a time in life where, if you're going to develop a mental illness, it's very likely to start in your adolescence. But it's also a time of heightened, we think it's a time of heightened plasticity, But it's also a time of heightened, we think it's a time of heightened plasticity. So it's a time of opportunity for things like learning and rehabilitation and therapy and that kind of thing. You mentioned the ratio between grey matter and white matter in the brain changes. So what is the difference between those two things? So grey matter is found in the surface of the brain, which is called the cortex,

So grey matter is found in the surface of the brain, which is called the cortex, and contains brain cells, so neurons and the connections between neurons and various other types of cell, whereas white matter is the long tracts, the fibres that connect up different regions of the brain together. And what we know about how grey matter and white matter change during adolescence is that grey matter increases during childhood.

It peaks, the amount of grey matter you have in your brain is at its highest in late childhood or early adolescence. And then it undergoes a very steady, slow and substantial decline right throughout adolescence. So in other words, during adolescence, grey matter is actually declining and then it stabilises in the 20s. Now that might sound like a bad thing. sounds like maybe it's kind of degenerating or something it's not but we know that because first of all it stabilizes in the 20s for many decades

and we know that the changes in gray matter relate to really important neurodevelopmental changes that are going on in the brain that allow the brain to develop according to the environment that the animal or the child finds itself in. Is it sort of chucking out the things that it doesn't need? Yeah, well, so one of the things that's changing and contributes to this decline in grey matter during adolescence is that synapses are being pruned away. So synapses are the connections between brain cells.

What the brain does is it massively overproduces the number of synapses that you need. So a child has many more synapses in its brain than an adult does. And so then what has to happen is that the synapses, the connections that aren't being used, need to be whittled away. And that is done via this process called synaptic pruning the synapses that aren't being used in a particular environment are the ones that get pruned away they get eliminated and the synapses that are being used in a particular environment are the ones that remain and get strengthened so it's a bit like a mobile phone or so it downloads all these hundreds and

hundreds of apps and they're all running away like mad in the background and gradually through adolescence and particularly towards late adolescence it's just getting rid of the apps it doesn't need yeah making it probably a more i mean we don't tend to use the word efficient but yes making it a more kind of efficient uh network of of um of synaptic connections the other the other thing that's happening is that white matter is increasing during adolescence. So the fibres that connect up different brain regions together are increasing right throughout childhood

and throughout adolescence and you can see that as an increase in white matter. And that makes the brain more speedy. It speeds up the time it takes signals to move from one neuron to the other. Matthew, yes. you and I. I think one of the things we need to think about is that we speak about teenagers,

and that's got a very clear kind of temporal definition, but teenagers were invented as a term in the 1950s, I think, and if you think about what being at that age, for most people still in the world today, it's not being relatively you know you've got lots of pressures on you in terms of survival in terms of working in terms of perhaps having a family that our adolescents don't have that pressure on them at least so the adolescence is a i wonder how much it is a social construct so there's physiological things going on but if

you think about it in evolutionary terms, then I guess that for most of our existence on the planet, then the people will be having children in their mid-teens. So whilst they're going through this turmoil, they've also now got to start thinking about the next generation. So, Sarah-Jane, how real is it scientifically and how much have we created it by the particular way that we organise our society at the moment?

Yeah, I mean, adolescence is a social term, it's a social construct. The end of adolescence, actually, we normally define as the age at which you attain a stable, independent role in society. So we can go on a long time. It's about 20 years. Yeah, or 50, let's say um but and you can yes like as you said you know there are huge current not just historical but current cultural

differences between societal expectations for this age group in our society it's completely acceptable to live at home and be in full-time education right into the throughout the teens and into the 20s in other, that's absolutely not the case, and young people are expected to go out and earn their own money, become independent, have babies as soon as they reach sexual maturity. Some people have argued that this suggests that this adolescent period is just a social construct invented, yeah, about 100 years ago in the US. But I think that's not the case.

I think there's really good evidence that actually adolescence represents a distinct, unique period of biological and psychological development. And that evidence comes from phenomena like we've already discussed, showing that firstly, adolescent typical behaviours like risk-taking and socialisation increase in adolescents, not just in humans, but in other species too. Also, cross-culturally, even between cultures that differ vastly in their societal expectations of this age group, you can nevertheless see similarities between adolescent typical behaviours

like risk-taking, sensation-seeking, and peer influence across cultures. And also across history, even as far back far back as well i've got a quote here from socrates um the children now love luxury they have bad manners contempt for authority they show disrespect for elders and love chatter in the place of exercise he was talking about adolescence do you think sometimes when you look back especially when you see teenage children you do slightly erase your own teenage experience? Yes, I know that I was a... But I was never like that.

We have a little trick we play. I think Doug Larson said that few things are more satisfying than seeing your own children have teenagers of their own. And Robin Winslet, the same sort of thing about when he became a parent and watching how his children dealt with their children.

I think it is. It's a way that we tend to sort of erase bits of our own childhood. And it's only sometimes, I think, when you watch our own children and then think, oh, actually, yes, I remember what that felt like. I think what I'm trying to approach is whether we know anything about the evolutionary reason for this change in in our brains i think what you've got underlying here sarah james outlined is a developmental process you've got a childhood or an infancy in which certain develop

you need to do certain things be quiet or just grow or whatever whatever the particular niche that you're in makes you want to do. But then you've got to become an adult, and that involves some fairly rapid developmental and hormonal changes, and that's what causes the upheaval. In our case, it's about acquiring life skills, isn't it? It's about becoming yourself. Yes. You would ask, what's the point of this period of life?

What's the point of adolescence? One of the points is to become independent, independent from your parents and from your families. And in order to do that, you need to be a bit risk-taking. You need to experiment, explore your environment, and you need to affiliate with your peer group. You need to establish yourself in the social hierarchy. So from an evolutionary point of view,

those kinds of adaptive needs might explain things like increased peer influence and increased risk taking during during adolescence which we see across species. I was going to say it's interesting so in a way it's not the teenagers that are the problem they're doing what they they are programmed to do they are developing socially hormonally all of those things at once it's actually the parents that are the real problem. In fact, Steve Peters, who wrote The Chimp Paradox, got a lovely view of this. He said, it's actually not the teenagers, it's the parents and their rhetorical questions.

But they say, are you stupid? To which the answer is, yes. Yes, we're stupid because we're finding out what stupid is. We're finding out what is stupid and what is sensible. The other question, don't you think? Well, no, because they're at a stage in their lives where they're finding out all those processes so leave them alone in their bedroom and don't worry about what they're doing i wanted to ask you matthew talked about the uh the different stages of our lives and i wonder when you're putting together

an impression about someone well Whether you consider this person, do you see them as kind of a four-dimensional object? I think Donald Trump has a very teenage brain, let me tell you. I look at that, I have a brain, I call it Semtex. Because it's plastic and it's explosive. So I think that deserved a better laugh. But anyway. Wow, I have never seen that work before I think that deserves a better laugh

and they just went, yes, you're right They're going to make a film and I'm going to be played by one of the great Hollywood actors Macaulay Culkin He's a little older but I think he's got the character. Comparing Donald Trump to teenagers

is just insulting to teenagers. That's true. I wanted to ask, Sarah, in your book, we've talked about a lot of these ideas of the behaviour of teenagers, but you're actually testing them in a scientific a scientific area for instance as you said that the mixture of both peer pressure and risk taking that you have worked on various different ways of trying to work out how much it is innate risk taking how much it is peer pressure risk taking can you can you run us through you

know at least one of the experiments that you used yeah so um well if you think about the the kinds of risks that we worry about teenagers taking so things like smoking or experimenting with drugs or dangerous driving binge drinking these are risks that they don't tend to do when they're on their own in fact we don't tend to do when we're on our own generally but teenagers particularly it's when they're with their friends that they might experiment with these risks. And it's been shown many, many times by lots of different experiments and in real-world data, which I'll come back to in a second, that's true, that if you take a teenager on their own and you get them to do a risk-taking task when they have no distractions

and they can concentrate on the task at hand, they don't tend to take more risks, actually, more often than not, than adults do. But if they have their friends with them, that's when they have this tendency to take risks. There was one nice experiment by a colleague in the US called Larry Steinberg. He got teenagers and adults into his lab. They took part in a driving game, like a video arcade driving video game. And they either did this when they were on their own, or they had a couple of friends standing behind them. And in the condition in which they had a couple of friends standing behind them, teenagers took about three times the number of risks that they took when they were on their own. Whereas having a couple of friends standing behind them

had no effect on the number of risks adults took. So it really seems to be critical in whether teenagers take risks is whether they have their friends with them. So it really seems to be critical in whether teenagers take risks is whether they have their friends with them. And it makes sense in terms of peer pressure because if the evolutionary pressure is to be accepted by your peer group and not to be ostracized by your peer group, then you need to be really aware

of what your peer group want you to do. And so you're much more likely to go along with your mates and do things like experiment with things that they're experimenting with so for example one one example i often give is a very intelligent uh say 13 year old girl who knows all about the risks of smoking nevertheless when she's out with her friends at the weekend and they're all smoking and they offer her a cigarette for her her, what's the more risky decision? Saying yes to a cigarette, even though she knows the potential health risks of that, or saying no and risking ostracising herself from her peer group?

Or we would argue that for a teenager, that's the bigger risk. It seems to me there are almost two sciences here. There's behavioural science, observing the way that people behave, the sciences here there's behavioral science observing the way that people behave but also this rather newer area of scanning the brain and looking at the physical changes in the brain so are those two approaches now beginning to coincide yeah and in fact what's interesting is i think um one has kind of triggered the other to some extent so like i mentioned until about 20 years ago, we had no idea that the brain changes after childhood.

We had no idea that the brain undergoes so much development during the teenage years. Because of those findings, which have now been published in hundreds of different papers, that lots of different regions of the brain are undergoing very substantial and protracted change, that has triggered a whole new field of behavioural science of teenage development. Because the idea is, well, you know, if you're, say, undergoing very substantial and protracted change, that has triggered a whole new field of behavioral

science of teenage development. Because the idea is, well, you know, if you're, say, let's take the social brain, because that's what I work on, if your social brain is changing so much during the teenage years, then presumably all the social behaviors that rely on the social brain must be changing too. Whereas prior to that, it was assumed amongst most developmental psychologists that social behaviors like mentalizing, the ability to understand other people's minds, was pretty much fully developed by age five or six. Now there's a whole new science of behavior of mentalizing and how it develops during adolescence. In other animals, non-human species, do we see this complex interaction between behaviour and physiology and development? Is it common really to most of, certainly higher

animals, all the way down I suppose to insects? Well certainly as I said then mammals are going to have very very similar physiology so the process of becoming sexually mature, which is what is underlying all this, of course, and the passage from infancy to adulthood, there's going to be common effects and those hormones are going to have common effects on the brain. In other vertebrates, it's going to be more complicated, but you see similar effects.

For example, there's a species of bird called the Florida scrub jay, in which the parents are often helped by their offspring or by other young individuals to rear their babies. So there are individuals who don't reproduce for a year or two, but are effectively in this kind of limbo between being a nestling and being an adult, in this kind of limbo between being a nestling and being an adult and they're contributing to the success of this of their parents helping them or just learning life skills about how you are you can be a successful bird in very very difficult environments. Rory I wondered when in terms of your risk taking as a teenager a little bit like the Quentin Crisp quote you were saying there's a strange thing where in one way teenagers appear to take great risks but another time you won't

take the risk necessarily of you know putting your hand up with the wrong answer in because it has this this clash of i wonder you as a performer sometimes as brian mentioned in the intro there's this idea of a perpetual adolescence this desire to show off in terms of risk taking you as a you were very young when you you know you you impressionist you had a hit single with a 19 parody when did you did you would you see yourself as a risk taker well i think looking back and this is something i've come to understand a little bit more with my experience with adhd more recently looking back because a relative of ours was diagnosed with that and i looked back at my own childhood, and I realise how much of that was to do with ADHD.

As a child, I was sort of quite scatterbrained, forgetful, but I was very impulsive and I was very impetuous and a bit of a show-off and sort of kind of irrepressible. And, you know, sometimes, you know, ADHD itself, it's not about bad parents and naughty children. It's actually a neurodevelopmental thing. So there's a big read-over into... We're talking about teenage, where all these things are developing, where you're going from a brain which is regulated essentially around emotions

and around the limbic structure to a brain which is regulated by analysis and and being rational and i think in the case of adhd people that go on into adolescence and into later life you never quite lose that impulsivity that that bit that actually regulates impulsivity um is still absent so for i once said to my agent i said you know how many of your clients do you think actually have adhd she said most of them because it's a very useful thing for a comedian to have. If you are naturally impulsive, naturally a bit of a risk taker, naturally a bit of a show-off, you will get to a joke more quickly.

You're making those connections very quickly. Sometimes a joke is just you're saying what other people are thinking, but they haven't dared to say it, or they haven't quite got to the stage where they're going to vocalise it. And a lot of that is to do with impulsivity. So in a way, the child that I was led to the adult that I was. And like a lot of people with ADHD, I found a job or I found a lifestyle where it's an asset to be impulsive. And it's an asset to have a brain that jumps around all over the place and makes connections.

The elements were there when I was a child and I'm not sure as a child or even as a teenager I knew who I was or what I was doing and even now I'm not entirely sure who I am or what I'm doing because I've now turned it round and it's now what I am

and who I'm doing. Sarah, what do we know about why, you mentioned schizophrenia earlier, for instance, that's a late teenage that appears to be observable. What do we understand about why it would be at that stage that schizophrenia will become observable? Well, yeah, schizophrenia is the reason I became interested in adolescent brains, in fact, because I was doing a PhD in postdoctoral research on schizophrenia, and I got interested in the fact that all these patients I was testing in hospitals in the UK and in France, where I did my postdoc, when I asked them, what age did you start experiencing your symptoms, which were things like hearing voices inside their heads

and being paranoid, there wasn't a single exception. Every single one of the hundreds of patients I saw said some age between 18 and 25. So I became interested in what is it in the teenage brain that develops differently in teenagers who go on to develop schizophrenia. And back then, that was about 17, 16, 17 years ago that I became interested in that question,

very little was known about even how the typically developing brain changes, let alone in teenagers who go on to develop schizophrenia. So that's when I decided to work on that precise question. The answer is we don't really know yet. That kind of question is starting to be asked in big, large-scale studies that are scanning the brains of teenagers, for example, who are at high risk from developing schizophrenia

or, indeed, another mental illness. And so the jury's out. We don't really know that the the precise answers but what these studies tend to show is that the way the brain gets to its end point so the way it develops seems to be really critical in all of these different mental illnesses and also developmental conditions even like adhd and autism it's not about the end point but it's about how they got there the analogy I like to use is whether you take to get to your end point whether you drive

the motorways or the a road roads you might get to the same point even in the same amount of time sometimes but the way you the route you take is really important and that seems to be the case for mental illnesses so is the the suggestion that a large amount of our personality as an adult is driven very much by the physical changes that happen in these years as the brain changes through the teenage years? Yes, but the physical changes that happen in your brain during the teenage years can of course and are necessarily moulded by the environment that you grow up in and the experiences you have so it's not just a biological kind of deterministic route it is very much influenced by your social and your environmental experiences i'm interested in this idea of an

end point you mentioned it a few times i mean is that the right way to think about it, that really my brain is pretty much fully formed by the age of 23 or 25. How much, in percentage terms, how much has it changed? How much has it continued to change throughout our lives? No, actually, that's probably really... I'm sorry if I've been using that word, because actually that's probably a really bad way to think about it. And I'm often asked, well, when does the brain become adult? I'm asked this question by people

who are interested in things like what age we should be able to vote or the criminal age of responsibility that kind of thing and you know so they ask well what age does the brain become adult because then we can use that point to determine what age people should vote or something like that but actually that's it's sort of a wrong way to think about the brain because the brain never stops changing to a certain extent. Right throughout adulthood, the brain is capable of change. So anything you learn, and there's no age limit to learning, is because of something that's happening in your brain,

a change to a few thousand synapses, say. Rory, having heard this discussion, and obviously I know it's something that interests you, how do you think this changes the way that that parents you know should interact with their teenagers because i mean in one way you could just go oh don't worry darling i know why you're behaving like this i've seen the mri i don't think that i have an inkling that won't wash with them so but you know what i mean so many parents used to think well you know you have children but where's the instruction booklet you know i think this is the instruction booklet because even you know just doing the preparation for this program uh it made me look

at my daughters in a totally different way one is 14 and one is 16 and it you know people say although as sarah jane said at the very beginning people oh it's hormones and and you know it's difficult teenagers but now when you understand what is going on in the brain as we said very early on the emotional changes the physical on in the brain, as we said very early on, the emotional changes, the physical changes, the hormonal changes we mentioned as well, but the speed at which the brain is developing and adapting to all these things. I almost want to go back and apologise and say,

no, you know, I understand. But of course we don't understand, that's the point. In the light of this research, could you see a time when we understand this developmental process better, that we change the way that we run society, we change the way that we educate children and teenagers in the light of our enhanced understanding? I think so. So the way I see it is that we place a lot of expectations on teenagers. And I think that might be because they, you know,

when they've gone through puberty, they look like like adults so we almost expect them to be like adults to make adult decisions to be able to plan like adults but in fact their brain is not adult at all the brain still has a long way to go in terms of development unlike younger children who very much look like little children we don't expect them to plan their day or plan their week we do that for them we make their decisions for them we stop them taking risks we in contrast allow teenagers we give them a lot of autonomy and we allow them freedom to make their own decisions perhaps we need to adjust the way we place these high pressures and high expectations on teenagers in society and in schools for example also um including i mean i I think I would have found all this information about the teenage brain really useful when I was a teenager.

Because, you know, it's not that difficult to remember what it's like to be a teenager. It's a pretty hard time for a lot of teenagers. There's a lot of turmoil and a lot of change. And to know that this is a natural part of brain development, I think would have been pretty useful, at least for me. And so, you know, including it in the school curriculum might not be a bad thing.

I think the other thing, on a rather more serious note, is that, exactly as you've been saying, that this is a crucial period where mental illness can develop, and I think both for children, teachers, and for parents, just to be aware of that, and without developing a hypochondria about any slight change in behavior that you really need to listen and think about what could be happening and to seek help if you've got the slightest doubts because this is a it's a

tremendously fragile and dangerous moment for for children has been all through the ages and as i said earlier on, there may be more pressures now because of social media. And so you can actually now get peer pressure from bazillions of people all around the planet, not just your mates in the schoolyard. So I think that for me is the really serious lesson that parents need to think very hard and teachers as well.

Well, it also strikes me that if you're asking people to have gone through their gcses and a levels and actually their degrees and pretty much for most people completed their formal education before their brain has fully formed into an adult brain it doesn't seem to be the most sensible way of running a society there's a whole lot of teenagers now who are considering a class action. Always enjoy that moment where Brian Cox says, I don't know. It doesn't happen that often.

It's always a fun bit. I don't know. We've run out of time, but Matthew, we can never let you get away without talking about your research area, which is primarily maggots, the world expert on maggots. I was going to say something because it struck me. You were talking, Sarah-Taylor, about the problem about the resolution there is at the moment for MRI scanners. So you can't see the fine level cellular changes.

But, of course, a maggot is simply, as you remember from reading The Hungry Caterpillar, the maggot is simply there to grow. It is a growing machine. Its brain is growing all through that time. And we can indeed resolve the maggot down to single neurons and see how they are changing and how the pruning that you described early on is taking place as well. So it may well be, in fact, the insights into the developmental processes and how the brain changes over time are going to come from very, very simple organisms like the maggot, like the fly, which are changing. They're not simply little robots.

They too are influenced by the environment and their growth patterns. And understanding the cellular changes is going to be much easier in a very simple organism, even if it doesn't want to storm off into its bedroom or do anything silly like that. They are going to be similar fundamental processes taking place in a simple organism as there is in our cells. How many neurons

does the average maggot... The maggot ends up with about 100,000 in its brain. It then kind of, of course, because the maggot has turned to a fly, so it then kind of melts some of them, but basically the maggot brain is the scaffolding around which the fly brain, which is perhaps three, four hundred

thousand neurons, is then built. Then that might sound like a lot, but the human brain contains about 86 billion neurons. So we have no idea how a maggot brain functions. So there are colleagues in America at a place called Janelia Farm who have made the wiring diagram of a maggot. That's one maggot. They got a maggot, they sliced it up, and they're working out

how all the cells develop. And they still haven't finished working that out yet. And then, when they actually know how the cells interact, then there'll be the possibility of modelling it. But the idea of understanding what's happening in the human brain or the mouse brain, that's decades, decades away. But we're not too far away

then from modelling a maggot. I reckon maybe within 20 years, yeah, that might be possible. Exciting times to live. Exciting times to live. And that maggot will be the Republican candidate. Yeah. Rory, one very important question, I suppose, for you, really, at the end of this, is I know you didn't have him in your repertoire, but once you found out you were coming on this,

you were working on your Brian Cox voice. It's still a fucking progress. Well, mine, I'll give you... Yours is very good. I'll do a worse version, right? This is because he always says mine's too fake. The universe is very shiny, but some of it is dark and scary. Ooh. How can I top that?

It's basically Orville. Where have you got to? I'm fascinated to know. Well, what do you think, Brian? Well, I think that's rubbish. Do you hear him? I think that's rubbish. That was actually me doing that.

You thought it was... Well, what I love is it's the mancunian wonder of the universe yeah um i can't top your approach it's not it's the worst question you get as an impressionist two things happen to an impressionist firstly this happened when i went i did the royal variety show once and i was really nervous and the wings about to go on and somebody came up say you're nervous i said yeah they just said don't worry just be yourself and the other question is is there anybody you can't do and you go yes and they're not going to go do them because no i can't do them so um yeah that's i'm afraid yes but i'll work on you see the part of the part of the purpose of purpose of doing this john burke john fortune once said um you know you're like you're like uh

david attenborough with the politicians. And he said, nobody ever accused David Attenborough of getting too close to the animals. So really my purpose on this programme is to study up close. And I'll pronounce maybe in the next series on my findings. You know what you've got, though, that Mancunian thing. Because when we had John Ronson on the show as well, people wrote in and complained that they couldn't tell the difference. Because John Ronson has a voice like that. When I was working on an Ian Paisley show,

and then they couldn't tell the difference between him and Brian. It was a lovely moment. It's so good, isn't it? So what is it? Because it's different from Yorkshire. You start in Yorkshire and it's all wines and then you get a bit nasal and all. And it's just, you know, there's something about that Manchester accent

and it's just, you know, it's an upward inflection and it's gentle and it's, oh, it's just, you know, there's something about that Manchester accident. It's just, you know, it's an upward inflection and it's gentle and it's, oh, it's fascinating. What you have there as well is just that little inkling there of the cricket commentating Brian as well. This is, we had a question from the audience. It's not a question from the audience. We don't allow that kind of thing. We gave the audience a question.

We asked them, what did you do as a teenager that you wish you hadn't? And looking at the fact we've got fewer answers that have been handed to us than normal, I imagine many of you were tremendously honest and our producer went, well we can't give that to them. So, I'm still a teenager,

and I think I've done everything I've done is right. Turn the fire hose on at school to see how long it would take for water to come through the coils. Try to drunk email Brian Cox at 3am asking for work experience. P.S. You never got back to me, Harry Willis. So, yeah, the question, what did you do as a teenager that you wish you hadn't?

This is looking like John Lennon in brackets. For the record, I'm a woman. Paid full price for a D-Ream ticket. So, next week, we're going to broaden out the peculiar behaviour of teenage humans to doing the peculiar behaviour of all animals with a panel that includes a head of zoology and the founder of the Sloth Appreciation Society. So they're bound to be late. And we still have a question,

which I read about this from a sloth expert once which is can sloths really survive a nuclear war so we'll find that out next week if the ethics committee give us permission i don't see i don't see a problem with it actually well cruise missiles are really accurate aren't they she's put it on a pacific atoll take it out. It could happen any moment now. Don't joke about it. Little rocket man, Cox. He's going to launch that missile. This is a simple experiment, Don. I like the simple ones.

Thank you very much to our panel. Matthew Cobb, Sarah Jane Blakemore, Rory Bremner. Thank you very much for listening. Bye-bye. Well, Adam Rutherford, that was a marvellous episode of The Infinite Monkey Cage, wasn't it? It was, Hannah Fry. Not necessarily the best ones, because I think the best ones are the ones that you were on. I like the ones that you were on. Yes, but if you enjoyed those episodes of The Infinite Monkey Cage that I, Adam Rutherford, and you, Hannah Fry, were on,

it turns out that we've got a whole eight series worth of just us. Yes, we do. The Curious Cases of Rutherford and Fry, our very own science podcast in which we investigate your questions. Questions like, does Kate Bush have a secret sonic weapon that she's trying to use to kill all of humanity?

We did answer that question. What about, what would happen to Hannah if we threw her into a black hole? Specifically me. I wasn't particularly happy about that episode. That's The Curious Cases of Rutherford and Fry, which you can download from... Your podcast providers. This is the BBC. In our new podcast, Nature Answers, rural stories from a changing planet, we are travelling with you to Uganda and Ghana to meet the people on the front lines of climate change. We will share

stories of how they are thriving using lessons learned from nature. And good news, it is working. Learn more by listening to Nature Answers wherever you get your podcast.