Fifty years ago today, University of Otago researchers began to study over 1,000 Dunedin babies born in 1972 and 1973.
The Dunedin Study, as its known, is now the world's longest-running multidisciplinary human health and development research project.
As children, participants in the Study were assessed every two years, then as adults every five to seven years.
The study of their life stories is still providing incredible insights into mental health, oral health, addiction and much more.
More than 1,400 peer-reviewed scientific journal articles, books and reports have been published by the research team.
Yet despite the Study's contribution to science, it is at its heart a very human story, says its director, psychologist Richie Poulton.
“I mean, 1,037 babies born 50 years ago have committed from that point on to giving themselves up to us to [be asked] 1,000 different questions, quite intrusive questions and to be poked and prodded every so many years so that they can essentially help others. That's their main motivation.
“That's why they've contributed so much. And, from our point of view, as researchers, we're very human too, we're not labcoat people that are indifferent and aloof, we have a very special relationship with our study members based on trust, and you don't get trust or achieve that level of trust unless you are very real, very authentic.”
- Listen: Dunedin Study shows a shift in family structure dynamics (August 2021)
The participation rate in the Dunedin Study is extremely high, Poulton says, with around 94 percent of the original participants still alive.
“Some participate, I think, because they like coming back. They feel respected, affirmed.”
Some of the cohort live on the margins of society, he says.
“It's nice for them to have a day where they are special and respected and valued.”
But the main personal motivation for the subjects, Poulton believes, is simply taking an opportunity to help others.
“There's just an incredible reservoir of goodwill to fellow men and women amongst this cohort. There’s a superb preciousness about this group of 1,000 who have committed so much of their lives to helping others.”
Poulton guards the anonymity of the participants fiercely.
“We ask people incredibly intimate details of their life. And there's an ironclad bond between ourselves and them not to divulge any information about them under any circumstances.
“I'm notoriously difficult on this particular point, I’ve had press people over the years harangue me about it.”
A Time Magazine reporter once tracked down some of the participants, he says.
“He stood on a corner of George Street and St Andrew Street and asked everyone at that point - if they looked 21 years old - whether they were in the study. He identified a couple of people, did a terrible character assassination of one poor person who had lived a hard life. And that's hurt them forever.”
The information Dunedin Study participants divulge is deeply personal, Poulton says.
“There's not an assessment that goes past without some study members telling me when I meet them that they've told our interviewers, something that they've never told another living human being, including their spouses.
“So, it's a very deep study. And it relies upon that really sacred bond of trust between ourselves and in the study members.”
Noelle McCarthy visits the Dunedin Study for the RNZ podcast A Wrinkle in Time:
Over 50 years, some of the Study cohort have died and those losses are felt keenly, he says.
“It feels like an extended family, in a way, and we feel the grief, it's palpable.”
In 37 years of working on the study, Poulton has glimpsed many insights into the human condition.
“I know from this work just how precarious life is for so many of us. We all like to present ourselves to the world in the best possible light, it's natural. And so, you see people walking around doing their business going about their life and looking pretty good and feeling pretty good and things seem pretty on the up. In fact, they're just hanging on by the skin of their teeth.
“So I've formed a view, a very basic kind of insight, which is to be human is to be vulnerable. And I really get annoyed with people who shy away from vulnerability in terms of public rhetoric and stigmatise it and the like.
“Most of us at some point in our life hit a low ebb, and that's natural, that's normal. And we should not be ashamed, we should be able to seek help talk about it, be open about it. That's what life is like. It's not a cakewalk.”
This is what makes the cohort’s determination to keep helping the study so admirable, Poulton says.
“When you think about the tough life some of them have been leading, and have led for a long, long time, they get up in the morning, dust themselves off and front the world.
“And when we asked them every so often to come back and put up with us for a day and a half, they do it willingly. And they do it with good humour and grace and great courage.”
What other big themes has he gleaned from the Dunedin Study over the years?
“The old nature-versus-nurture debate has been raging for hundreds of years and it's usually cast as nature-versus-nurture, which one is more important in determining how our lives turn out.
“And that's a silly notion. It's the combination, we've shown this, both in terms of why people perpetuate the cycle of violence, why people become depressed in the face of life stress, for example, it's the combination of both what you're born with, your genetic endowment, and what happens to you in life, that is the environmental nurture components.”
This gives Poulton cause for optimism.
“Much as you can't change your genes easily, you can change the environments that people are exposed to. And so that should give hope, to all interventionists, policymakers, practitioners, parents, whomever, that by improving environments in a generic sense, you can actually make people's lives better in the long term.”
When difficulties arise, early intervention works best, he says.
"If you intervene much earlier in the life course - that is with children as opposed to young adults or older adults - simply because children are more porous to the environment, they are more susceptible to learning.
“And they can see you're likely to get more fundamental change if you start early. That should, of course, inform public policy that should be tilted towards the earlier part of life.”
Technological advances over the last 50 years have shaped the Dunedin Study, Poulton says.
“We've got increasingly sophisticated physiological equipment that we can bring to bear in terms of assessing physical health.”
The cohort, now in their middle years, are ageing at different rates, he says.
“Our focus, given that people are entering their midlife years, is trying to understand why some people are ageing, biologically that is, faster than others. Because it's those people that are rapidly ageing who will end up susceptible to all the non-communicable diseases like heart disease, risk of stroke, diabetes, lung disease and the like.
“And if we know who's at risk for that before it actually happens, we can inform intervention efforts to try and either slow the ageing process or to prevent the onset of diseases.”
Poulton was a “callow 22 -year-old clinical psychology student” when he first became involved in the Dunedin Study.
“It's been a professional love of my life. It's been incredibly rewarding in all sorts of ways, it's opened many doors.”
