The Dunedin Study is one of the world’s most well-known longitudinal studies. This year the study and its participants turn 52, and a new director – Professor Moana Theodore – takes the reins.

In 1972, the participants of one of the world’s landmark longitudinal studies, the Dunedin Study, were born. And for over half a century, a study from the university at the bottom of Aotearoa has been influencing opinion, policy and understanding across the world. 

Created with a goal to study developmental and health problems in just over 1,000 children between birth and three years old, the Dunedin Study was not initially meant to be this long-term. Founding director Dr Phil Silva may not have guessed then that 52 years later, those 1972 babies would still be taking part in what is widely considered the most detailed study of human health and behaviour in the world.

When Professor Moana Theodore (Ngāpuhi) first touched the Dunedin Study, she was 23 years old, interviewing the participants as they too navigated their 20s. With a curiosity for human nature, Theodore’s interest was piqued by this mahi.

“Working at the Dunedin Study – which was world leading then as it is now – I could see the huge potential to undertake important research looking at human health and development,” she says.

In 2007, she once again joined the Dunedin Study team, doing postdoctoral research with the study’s second director, the late Professor Richie Poulton.

Now, 26 years after that first encounter, Theodore has returned to the study as it enters a crucial 52nd year of assessment. This time, as its third director.

Growing up in South Auckland, Theodore saw many of the real life effects of inequality in the communities she lived in, but also considers her upbringing in this diverse area of Aotearoa an “amazing, multicultural” one where she was supported by whānau and community. 

The perspective gained through this upbringing and through her experiences as a wahine Māori have had an impact on how she views the study and its implications.

“I’ve been fortunate to have seen a wide range of lives and circumstances, and I think that gives you an understanding of why people face the challenges that they do.

“Looking back now, I recognise the impact on many of those families due to issues like poverty and the resultant loss of potential. And so I definitely think that my background and who I am has affected how I view the research and the impacts of issues like poverty within our society.”

And being the same age as its participants also gives Theodore a unique perspective from that of her two predecessors. 

“For the first time the study has a director that is the same age as the study members, and that certainly may have an impact on how I think about the study. That focus on what can we do to address inequities, health inequities? How we can ensure long term positive ageing is certainly a key area of focus of mine, and has been for some time.”

Despite the study’s goals changing over time just as its participants’ lives have changed, Theodore recognises the ongoing legacy of the Study and its key questions.

“From its earliest stages, it’s asked the question: how do we support positive health and development?

“We will continue to do excellent research. Research that makes a difference that could inform policy and practice in and around what happens in the early years – how can we support a healthy childhood? And then, how can that be related to what happens to us when we become adults? And now we’re increasingly looking at ageing.”

And over the course of its 52 years, the Dunedin Study has done its fair share of informing practice and understanding of issues such as poverty and the impact of childhood health conditions. 

Theodore says she’s immensely proud of the influence this work has had over the years, pinpointing its findings in the long-term outcomes of youth offending as one such crucial understanding. 

“What the study found was that a large number of teenagers, particularly boys, were getting into trouble in their adolescent years, but with time that would just naturally stop, it was almost like it was a part of development.”

A paper that came out of the study in 1993 has been cited “as a justification for reforming [countries’] juvenile justice system to be less punitive and more supportive to young offenders,” a former co-director of the study told The Guardian in 2022.

2024 brings with it a fresh assessment phase for the study, which will see participants coming back to the university over the next two years to analyse everything from physical health to mental and social wellbeing.

It’s a mammoth effort from the team at the University of Otago, conducting interviews and tests that have been in the planning stages for, in some cases, decades. For the participants, Theodore says, the Dunedin Study has been a huge commitment, not just in the time it takes for assessments every few years, but for the level of personal detail participants give to the study. 

“They have been coming in now for half a century, and they have been gifting knowledge about their lives in a really detailed way. They do it to help others… their generosity is why the study is so successful,” she says.

But for the participant retention rate to be as high as it is – over 94% at the 45 year assessment period – more than half a century on, there’s another side to that coin: the study takes care of its people.

“It’s a deeply human study, so the relationship with the study members is paramount.

“Our job is to ensure that wherever possible, each and every [study member] can participate,” says Theodore. This means while most of the participants travel to the University for assessments every few years, the few who can’t are visited at their homes. 

With this new phase of assessment set to kick off in April, Theodore is gearing up for the busy season. But as with most longitudinal studies, the work they’re doing now stretches far longer than this two-year assessment period. 

“Even though we are thinking about the current assessment phase, we also think about the next assessment phase after that, and the one after that,” she says. 

Having already exceeded many of its initial expectations, the Dunedin Study is set to proceed well into the future. Under the guidance of Theodore, the goal is clear: to continue to receive the gift of insight from study participants, and ensure this insight remains a benefit to others.

“We talk about the science, but underlying the science are those human relationships. It is a study about humanity, first and foremost.”