INTRIGUING MUSIC What is it that determines our personality? Our future health, wealth and happiness? In our journey through life, why do some people develop phobias and cancers, while others lead a well-adjusted, healthy existence? Why do some children grow up to become successful entrepreneurs or Nobel Prize winners, while others become drug addicts and down-and-outs? Are these things settled at birth or is it a result of our childhood experiences? It's a question that's fascinated philosophers and scientists for thousands of years. Hi. Uh, can I have a flat white, please? One sugar. It's also a question which fascinates clinical psychologist Professor Richie Poulton. Poulton's spent decades observing people everywhere from kindergartens to maximum security jails. I've always been curious about what makes people tick; the pathways that people take through life; how you get on to good pathways; how you maybe fall off those pathways. Why does one kid grow up to become a burglar and end up in the clink and another child grow up to be a great concert pianist? Is it genes? What you're born with? What you inherit from your parents? Or is it more to do with the environment? The things that happen to you as you're growing? Imagine if we knew the answer to that. One way to answer that question would be to take a baby and watch everything that happened to it from birth to grave. The problem with this approach is we would end up knowing a lot about one person, but nothing about the rest of society. If you really wanna answer this question, you need to take a large group of people, and you measure their life experiences in a great deal of detail, so that we get a comprehensive picture of the range of human experience to better understand, uh, what makes us what we are. In 1972, a medical school from a small city in NZ embarked on the ultimate nature-nurture test. They decided to take every child born in the city that year and follow them for life. For 40 years, scientists have probed every nook and cranny of their existence ` their medical history, their personality, their genes, criminal convictions,... Hands on your cheeks. ...relationships, successes, failures ` the lot. How many times have you sold hard drugs like heroin, cocaine or LSD? The experiment is called the Dunedin Study, and its subjects are now the thousand most-studied people in the world, and the richest source of information on what really makes us who we are. Copyright Able 2016 GIGGLING One, two, three. Go! Go! Go! Go! Professor Richie Poulton has spent his career studying human development, and he still finds kids fascinating. Everyone wants to know how their children will turn out. That's something I wanna know about my own daughter. What are the things that really count in life? Results from the Dunedin Longitudinal Study can already predict how some of these kids are going to turn out as adults. It's amazing what we can tell about these kids already. Experiences and things they're doing is going to echo down their life. You can tell, for example, some kids are likely to end up in` in trouble with the law if they don't watch out, and the important thing is knowing that early gives us a chance to avert that, to change that life trajectory. INTRIGUING MUSIC But the Dunedin Study is not just about growing up in NZ. It has something to say about all stages of human development everywhere. It's now regarded as an accurate predictor of life in any Westernised nation, from the affluent of Zurich to the penniless of Pittsburgh. Lots of longitudinal studies measure just a couple of things, whereas the thing that's special about the Dunedin Study is that we've measured multiple aspects of human health and development, and so we get a complete picture of people's lives. The thing we're gonna be looking at, Barbara, is where you've been living. As well as measuring physical data, the study also investigates subjects' personal lives. ...street or perhaps in an abandoned building... Jobs, relationships, drug and drinking habits, even criminal activity. Some of them have jobs that are really hard to code officially. We know, for instance, that there are cannabis farmers in the study. There's no other study in the world that gets the kind of valid data on... undesirable behaviours that affect our health that the Dunedin Study gets. We asked the study members about risky sexual activities, uh, that` I don't have to go into detail about them here, but you can use your imagination. Nothing is off limits. The trust is so solid that study members even admit to serious criminal offences without fear of prosecution. We have on record study members' confessions of capital crimes, and those are protected. We will never ever share any information about our study members with anyone. This confidentiality is one of the secrets of the study's success. In fact, none of the adults shown here are study members. They're all examples from real life. Four decades ago, when the study first started, it uncovered something unexpected ` a disturbingly large number of undetected health problems in children. I'm just shining a light into your ear here so I can... By the time they were 9, a quarter had suffered from glue ear, one in 10 had eye defects... What is a clock? ...and a staggering 25% had language problems. More reassuringly, the study has found caesarean birth or being left-handed has no lasting effect, and bed-wetting and thumb-sucking are passing phases with no psychological significance. Those initial findings were just the start of what was soon to become an avalanche of information. The study has now published 1500 papers in major scientific journals, an average of a paper every 13 days for 40 years. Those scientific articles cover virtually every aspect of human health and behaviour. The study reveals what underlies heart disease and asthma, why teenagers run off the rails, and how to spot future criminals in kindergarten. It even predicts unemployment and illness decades before individuals actually experience them. They've discovered everything from a gene for violence to a connection between the amount of sunlight a pregnant woman gets and the height of her children when they grow up. The study has also discovered there are differences in young children's personalities that will have profound consequences for them in later life. 1 Boohoo! I've been left on this strange doorstep. Gurgle, gurgle. These kindergarten children already have their own unique and distinctive personalities. Who is it? The wolf. It's the wolf. The Dunedin Longitudinal Study has discovered that even at this age, children display character traits that accurately predict their health, wealth and emotional lives as adults. ...long sharp teeth and a mean expression on his face. There are personality differences between children that are really terribly consequential. There's something about the characteristic ways in which children behave, think and feel that is going to have huge implications for what happens to them. Wow. CURIOUS MUSIC The Dunedin Study found it could classify children into five basic personality types, and these early character types persist into adult life. EXCITED CHATTER The five personality types are well-adjusted, reserved, inhibited, under-controlled and confident. As a kid, I was always fascinated with speed. Then the wheel was invented in my childhood. There was bikes and trollies, and you could go as fast as you liked, or as fast as the` the hill would let you go. I was quite competitive, so I wanted my trolley to be the fastest. To be the fastest, there's a little bit of innovation, so I made the` you know, the back axels a bit wider than the front so it wouldn't roll. I was very confident, and, uh, it's just sort of continued to this day. AJ Hackett is the entrepreneur who gave the world bungee jumping. He's created an international business based on his love of thrill seeking. Pretty much everyone on the planet now knows what a bungee jump is. Three, two, one. (SCREAMS) AJ fits the profile of the confident personality type. Around 28% of the population fall into this category. They're go-getters. They're the entrepreneurs. They're not afraid to take on challenges. They're not necessarily, if you will, the life of the party, um, but they're people with a presence. The second personality type the study identified is less outgoing. We have another group of individuals who are more reserved. They're somewhat timid, but not to the point of being paralysed by their timidity. My friends would probably describe me as` probably quiet. My natural tendency is to want to sit back, watch people, not talk, not really make conversation, especially in those new situations like going out to a party, going to a place where I don't really know many people. It's like I have to always override that natural tendency and make an effort. Julianne is classified as a reserved personality. Reserved adults make up 15% of the population. INDISTINCT YELLING Stay there, Rosie! Erin Harrison represents the third and most common personality type ` the well-adjusted. I would describe myself as a very organised person, very active, reasonably adaptable. Quite social, I guess, too. INDISTINCT YELLING There's definitely times when I stand at the front, I'm very confident and be the leader of the group. There's also definitely times when I'm the one at the back, kind of just listening. (LAUGHS) But I guess I generally just fit in to any situation, um, and go with the flow. Well-adjusted individuals tend to be flexible, resourceful and fit in well socially. They make up 40% of the population. The confident, reserved and well-adjusted personality types are generally productive members of society. Their mix of mostly positive character traits means they do well in life. They're more likely to be happily married, have friends, successful careers and enjoy better health. This is not the case for the final two personality types. The combination of character traits that define their personalities creates a great deal of trouble and angst, both for themselves and the rest of the community. SPEAKS JAPANESE 'Hikikomori' is a Japanese term used to describe young people who lock themselves away in their rooms, often for years at a time. It's an extreme version of an affliction seen in around 7% of the Dunedin Study members ` members identified as inhibited. It's one of two personality types that predict lifelong negative outcomes. This is an adult whose shyness begins to interfere with their ability to do very simple things. They have a hard time leaving home and establishing a life for themselves. They're fearful, anxious, neurotic. They don't like novelty. They're actually made quite uncomfortable. So it's that combination of being rather closed, um, to experiences and quite high-strung, uh, that really typifies what they're like, um, as adults. And, you know, they're also much more prone to develop depression. The inhibited personality is not the only character type that has a disastrous impact on a person's quality of life. School days, you had fighting from an early age. Even at primary, I can remember having fights with guys three years older than me all the time. Dan Wadsworth has struggled with self-control all his life. In his teen years, he was sent to jail for drinking and street fighting. '97, on my 21st, I got really, really drunk. I was noisy, obnoxious. I helped myself to the bowsers and just was sculling under the taps and, uh, ended up having an altercation with the barman, and I, um, hit him, which I got six months for. Dan represents the 10% of the population classified as under-controlled. They grow up to be high-strung, irritable, easily fly off the handle. Interestingly, they too are closed to new experiences. They don't like novelty. They don't like change in their environment. They become involved in antisocial activities. They have a much harder time adjusting, uh, to work lives once they leave school. They're much more prone to long bouts, um` spells of unemployment. Once I see red, I` I still struggle to control myself. Um, like, to be perfectly honest, I had a moment last night with a guy that I lent my car. He took two hours, and for the whole time, I was just stewing on it, you know, to the point where I'm like this, and shaking. I couldn't even talk, I was that angry. I was` It was, 'Eff, eff, eff. Get out. I'll smack ya,' you know, and I` I lost character, lost my composure. Couldn't deal with it. So that's me still dealing with it, you know. Yeah. Under-controlled adults are more likely to develop heart disease and diabetes. They also suffer more lung problems and STDs. One of the things that we know is that they're very impulsive. They're` They're prone to experience a lot of, um, anger, hostility, but they're also sensation seekers. And one of the things that happens with them is that they go out and they, you know, have unprotected sex and they start smoking earlier and they drink a lot more and they binge. Um, and that takes a toll on your body. What is remarkable is the Dunedin Study first identified these personality types not in adults, but in preschoolers. And they stayed the same. Our temperament at 3 is our temperament at 23. That may be fine for the normal groups, but what are the implications of identifying young children as under-controlled or inhibited? If we see signs in children at this age, what should we do? It is a lot harder to change the person than it is to change what it is that the person does. By trying to alter a child's behaviour, you can change how it is that the world is responding to that child. It doesn't mean that you're changing the child's personality, but it does mean that the child is going to be reinforced, is going to be rewarded, is going to be punished for whole different, um, um, um, sets of behaviours. The Dunedin results show personality is set in early childhood and has lifelong consequences. The good news is other Dunedin results show a person's future is not a function of personality alone. The study has found there is something we can teach any child, no matter what their personality type, that will increase their future health, wealth and happiness. 1 Childhood is the dress rehearsal for adult life, an opportunity to practice being a grown-up, a chance to lay the foundation for later years, to experiment with independence, to develop life skills, overcome obstacles and deal with upsets and problems. (CRIES) How do you get what you want,... but still respect other people's rights,... Hey! He's got your car! ...settle disputes, argue, cooperate, find out how the world works? The power of a longitudinal study is that it can make connections between childhood and effects years later in life. It can spot patterns that are otherwise invisible. If you follow people over time, when you assess their behaviour when they're young, no one knows how they're going to turn out. It's completely unbiased. You measure it, and there it is. Then you wait several years and you follow them up and you find out which ones have developed schizophrenia, which ones have developed depression, which ones have developed diabetes, obesity. And the information that you have on what were their lifestyles and their risk factors from early in life are true predictors of their later outcomes. This approach led the Dunedin Study to uncover a series of unexpected links between childhood and problems in later life ` connections that were previously unnoticed. (LAUGHS) The history of science tells us that... all of us ` me included, you included ` see what we expect to see. It's only when discoveries are made that you see things that had always been there, but you didn't notice them. Did you have shoes, or did you have boots? Where did you put them? Are they your ones? No? What colour are yours? Most children take their first tentative steps around 13 or 14 months and are talking by 24 months. Yep. Aw! Well done. Well done! It's completely normal for children to hit either of these milestones at different rates, but the study found big delays in both milestones predicted problems much later in life. The clumsiness, the poor reflexes, slower to learn their language, all of those things point to problems in brain development. And for a portion of the boys involved, they indicated an even worse outcome. When they entered school, they had great struggle learning how to read. As a result, they disliked school. They didn't find it engaging, um, and they were ready to leave it as soon as they could. The boys were likely to do badly in school and later to be involved in criminal activity. This has created a chain effect. They had poor verbal skills to start with, then they lost out on education, which makes a criminal occupation relatively more attractive. So you can see that it starts out with something as innocent as delayed speech, and gathers, uh, force, if you will, over the c` over the life course. GENTLE PIANO MUSIC Dunedin researchers regularly measured how much sleep children were getting between the ages of five and 11. When they tested the same people 20 years later, they made a surprising discovery ` children who slept the least during their early years had become the fattest adults. The amount of sleep you get when you're a child will predict how overweight and obese you become by age 32. And that strength of prediction is on par with how much physical activity you do. Sleep influences hormones, and some of these hormones are critical in determining how hungry you become and also in signalling when you're full. Short-sleeping toddlers had other difficulties. They were more likely to have trouble with cognitive function during adolescence and anxiety problems in their 20s. SOFT MUSIC But it's not just everyday behaviour that produced unexpected results. Dunedin researchers were interested in some rare symptoms found in a small number of children. We wanted to know what happens to children who see things that are not there and hear voices. It's very rare. Most paediatricians never even ask about it. No one notices it. No one thinks to ask the children, but the Dunedin Study did. When the children were 11 years old, they were asked, 'Have you seen things that are not there?' 'Have you heard voices?' 25 years later, the Dunedin Study went back and looked at the same children as adults. What they found was unexpected. We found out half of them had developed the disease of schizophrenia. Schizophrenia affects more than 24 million adults worldwide, but this was the first time anyone had identified the symptoms in children. Prior to the Dunedin Study results, it was assumed the illness only existed in adults. The first time I heard about those results, I was very sceptical. I thought, you know, 'There's no way that can be true,' but it was very carefully done, uh, and has been confirmed in several other studies now. It is solid. So we've had to change the way we have thought about how schizophrenia begins. The results show schizophrenia doesn't begin in adult life; it's almost always preceded by developmental difficulties and minor psychotic symptoms in childhood. Up until now, they've been having to wait until someone with schizophrenia ends up in the hospital, and it's a bit late at that point. It now means that you could start to identify children at risk and get them some help earlier on, before they got so terribly, terribly ill that their whole lives were ruined. This new awareness has changed the thrust of medical research. Not all the people who showed these early risk characteristics developed schizophrenia. Now the question is not what is the cause of schizophrenia, which is much too simplistic a way, but what leads people to go from these early risk factors to overt schizophrenia, and we're only just beginning to get any kind of grasp on that. Dunedin researchers regularly measured the amount of television children watched as they grew up, and again, they found worrying effects. The more TV people watched as children, the more likely they were to have unhealthy cholesterol levels and be cigarette smokers when they grew up. But there was, however, a much more unexpected result ` the amount of television someone watches as a child also affects their later employment prospects and their income. The amount of TV you watch will predict down the track how you do at school, whether you'll leave with any qualifications. Beyond that, though, it will also predict how you do at university and whether you end up getting a degree. People who watched the most TV as children were three times more likely to leave school without any qualifications. Those who watched the least TV were four times more likely to graduate high school and go on to get a university degree, irrespective of IQ or family income. The American Academy of Paediatrics now recommends parents limit children's viewing to less than two hours a day. 1 INTRIGUING MUSIC The Dunedin Study's findings are now internationally recognised, but in the early days, there was reluctance to take the study seriously. Some thought that results from 1000 people in NZ couldn't possibly apply to people in other parts of the world. When I first started working on the Dunedin Study, I would bring the findings back to the United States, and people there had a` um, a stereotype. Everyone in NZ was wearing a grass skirt and paddling a canoe on the beach and drinking little funny cocktails with coloured umbrellas on them. It was really the success of the NZ Tourism Board in portraying NZ as a tropical Polynesian destination. # ...tangi mai te heihei. # Professor Terrie Moffitt set out to test if the Dunedin Study results could be applied elsewhere. She took the Dunedin findings about antisocial behaviour in boys and set about repeating the experiment with boys in a totally different environment. I identified a study of boys growing up in inner-city Pittsburgh, many of whom lived in public housing. Their families were supported by social welfare. About half of them were African American. And we repeated some of the same studies in the two samples ` one in Pittsburgh and one in Dunedin ` and the findings were always exactly parallel. Moffitt found the crime and delinquency rates in both cities were identical. 50% of all crime was committed by just 5% of males, and in both cities, the most delinquent boys came from the most disadvantaged social backgrounds. The findings demonstrated there are fundamental truths driving human behaviour, regardless of nationality or ethnic background. The significance of the study's findings was recognised when Dunedin researchers were awarded the Stockholm Prize for Criminality and the prestigious Jacobs Prize for ground-breaking research into youth offending. Honouring ground-breaking achievements... The prize was presented in front of a who's who of politicians and international scientists in Zurich. They have forever changed and improved behavioural science. The concern Dunedin findings might not apply further afield has now been conclusively settled. The study is truly unique, and now attracts millions of dollars in additional funding from both the United States and UK governments. The foreign funding agencies find it useful enough that they want to be stakeholders financially, and policy makers in` written in the United States cite findings from the Dunedin Study very frequently. The World Health Organisation cites findings from the Dunedin Study. So information is getting out there and being used worldwide, without concern for, 'Isn't NZ too far away?' That really doesn't come into it any more. There were, however, two significant differences between Pittsburgh and Dunedin ` homicide and suicide. Although the assault rates are identical in both cities, the homicide rate in Pittsburgh is dramatically higher. In the United States, firearm ownership is very common and the homicide rate is very high. In NZ, the assault rate is exactly the same. It's simply that assaults in NZ don't get converted to homicides because the weapons are not as lethal. The other notable difference between the two cities was the frequency of youth suicide. The youth suicide rate in NZ is higher than in other countries. That probably has to do with changes in the economy. At about the age when the Dunedin Study members were able to leave school and get jobs, suddenly all the jobs disappeared. A spike in youth unemployment in NZ coincided with a rise in youth suicide. In fact, some of the most interesting Dunedin results come from people in the most difficult circumstances. The people that are most often lost are not a random group. They are people in whom multiple problems tend to aggregate. These are people that live on the margins of society. They don't have a fixed abode. They don't have a cell phone. They're in and out of institutions. And most studies fail to find these people again and keep them coming back, whereas we have managed to keep everyone involved ` virtually the whole lot over almost 40 years. We've now been studying them for 38 years, and over 96% of them are still agreeing to take part. That's remarkable in this era when most scientific studies starting up, there's less than a 50% take-up rate. Most study members no longer actually live in Dunedin, but one of the secrets to the success of the Dunedin Longitudinal Study is that it goes to extraordinary lengths to keep participants involved. No matter where they are in the world, participants are flown back for every phase of testing, and for those in hospitals, prisons or unable to travel, the study comes to them. Last phase, I was the travelling interviewer, so I got to see some study members who were in prison, study members who were in institutional care, and some who for physical or other reasons simply couldn't travel. I recall one study member who spent much of his life in prisons and had really had a very difficult life, and he said, 'I haven't done very much in my life, but I've done this.' And he was damn right. In many ways, he might have done more for people than people who've lived a completely blameless life. 1 INTRIGUING MUSIC One of the latest and most exciting finds from the Dunedin Study is also one of the most surprising. It has huge potential to improve everyone's personal health and wealth and the power to transform a nation's economy. The study looked at success in life and asked the question ` is there anything in childhood that predicts who will be successful and who won't? Does it matter if your parents are rich or poor? How much does your IQ matter? Or is it how hard you try? It's a question that fascinates not just psychologists but also Nobel Prize-winning economists. A lot of unproductive social behaviours inhibit economic growth, so as we understand more deeply the structure of the human development process, we understand more deeply how to get more educated workers and how, therefore, to contribute to economic growth. Professor James Heckman believes that if we can understand what makes people successful or unsuccessful, then we'll have a powerful new tool to tackle major social issues. In many areas, whether it's criminology, whether it's in health, education, we typically treat the problem as it appears. So if we start going back and understanding where the problems came from, then maybe treating it and responding to it very early could be a very important social priority. So what is it that makes someone successful in the first place? My money was on intelligence as the best predictor of success in later life. I thought if we took account of children's intelligence, we would find that the bright children had a successful life and the dull children did not. But the Dunedin Study found the most powerful predictor of success in life was something else, something the study measured in 4-year-olds that, 30 years later, accurately predicted the income and job status of the same children when they were grown up. That measure was self-control. Are you in command of yourself or is yourself in command of you? And there are plenty of people out there who explode, and it's sort of like, 'I didn't choose to explode. It just happened.' Where other people may feel the same irritation ` even the same anger ` but take a deep breath and can down regulate that and control it. Now one of the interesting questions becomes what happens to 3-year-olds and 10-year-olds or adolescents who have a little versus a lot of self-control? The Dunedin Study was in a perfect position to answer that question, as it had been following the same people for over 40 years, and what they found was extraordinary. That self-control, measured for the first time at 3, is forecasting whether or not you're married or not, in a stable relationship, whether or not you have a good job history or a bad job history, and whether or not you're doing well health-wise or not. And that's remarkable to see that long legacy of childhood functioning into middle age, and into such a wide array of characteristics of who we are. One of the best-known demonstrations of self-control is the marshmallow test, first conducted at Stanford University in the 1960s. 4-year-olds were placed in a room with a marshmallow and given a simple choice ` eat the marshmallow now, or hold out for 15 minutes and then have two. Maybe now. Which either, 'I impulsively eat it now, because I can't control myself, 'or I wait and I get something better.' Can you constrain your impulses? Because everybody wants to grab it, um, and eat it. Some of the techniques that children use are very interesting. They look away. They distract themselves. Where one of the worst things you can do is just look at it and look at it and salivate, and then you can't stop yourself. CURIOUS MUSIC But the kids who developed self-control have already learned at the ripe old age of 3 or 4 not to look at it. Distract themselves, because they've acquired knowledge from those around them, 'Hey, you know, if I tell you you can't do something, don't go hang around it. 'Go find something else to do.' INTRIGUING CLASSICAL MUSIC Dunedin researchers first measured self-control when the study members were young children. What is startling is what those measures were able to predict about the children's future prospects. In almost every measure of success, self-control made a huge difference. Children who had high self-control at age 3 to 5, later, in their 30s, owned their homes, were business entrepreneurs, had solid jobs, had started saving for retirement and were considered good money managers by their friends, whereas study members who had poor self-control in early childhood were in trouble with debt, had had possessions repossessed, had bankruptcy problems, and they tended to be considered as poor money managers by their friends who knew them well. MELANCHOLY MUSIC For those with low levels of self-control, the problems are not just financial. The Dunedin Study discovered low self-control in children produced a raft of physical problems in later life. These include obesity, high cholesterol, high blood pressure, heart disease and sexually transmitted infections. Children with poor self-control are also more likely to grow up to be addicted to tobacco, alcohol or drugs. Bad-functioning psychologies and behaviours go along with bad-functioning bodies, not just in the here and now but over the long term, and that's an expensive cost for the individual, for the community and the society. To self-regulate, to self-control, whether you're talking about obesity, whether you're talking about smoking, whether you're talking about a wide variety of drug usage and so forth, self-control, self-regulation plays a very important role. EXCITED CHATTER The good news is that self-control is not fixed ` it can be improved. What promotes self-control or self-regulation in children? Well, we know from lots of work that sensitive, responsive parenting in infancy starts it off the bat. Being firm and consistent in discipline starting in the second and third year of life does it. Having peers who are themselves self-regulated and under control and enforce norms of social behaviour that say, 'Hey. We don't do that. You wanna be my friend, you're not gonna act like that.' So there are a multiplicity of factors. And it's not just the kids with low self-control who can improve ` anyone can. What the Dunedin Study suggests is that all children could benefit from learning better self-control skills. Even those who already have average self-control can get better, uh, to their benefit in mid-life. In fact, Professor James Heckman is using the Dunedin results and advising the American President to teach self-control in schools. He believes there'll be huge benefits to the US economy and the savings will be immense. No question about it ` billions. Trillions. When a pre-diabetic person is told, 'Lose weight. Exercise. Avoid certain risks,' many people don't do it. Who are these people? The ones who are unable to essentially regulate their own lives, whether it's in health, whether it's in` in a number of areas of life, and then you say, 'Can you do something about it?' You say, 'Is this a trait that you're fixed with? 'Is it set in stone?' The answer is no. These traits emerge, and we can do something about them, and that's the` that's the hope in public policy. (EXCLAIMS) Childhood is a time of hope and possibility for both parents and children. What are you gonna be when you grow up? Are you going to be in the circus or something? No. A train driver. A train driver? A policeman. Dinosaur hunter. One of the objectives of a longitudinal study is to better understand the challenging journey between childhood and adulthood. The Dunedin Study has found that many adult problems begin much earlier in life than we'd previously imagined, but the study also found overwhelming evidence of the benefit of a good start in life. Won't come as a surprise to know that having a good childhood, a balanced and predictable family environment where parenting is warm and sensitive and stimulating, sets people up on a really good life trajectory. At the start of this episode, we asked the question, 'What really makes us who we are?' The message is the same for anyone wanting to make a difference in people's lives, from parents to policy makers. Perhaps one of the most profound truths of the Dunedin Study is also one of the simplest. The early years are absolutely critical for how a person's life turns out, and if you really want to make a difference for people when they're adults or when they're old even, intervening early and getting that right is the key. That's where your money should go. That's where your focus should be ` those early years. They are seminal in all sorts of ways. (LAUGHS) Captions by Catherine de Chalain Edited by Ingrid Lauder.