Dunedin Multidisciplinary Health and Development Study director Prof Richie Poulton spoke about the internationally renowned study at the Institute of Public Works Engineering Australasia conference at the Dunedin Centre on Saturday.
He shared many of the reasons why the study was so successful, but kept going back to the dedication of its almost 1000 participants.
That dedication meant the more than 40-year-old study had an ''extraordinary'' retention rate of more than 90%, which was unheard of in comparable studies around the world, Prof Poulton said.
The retention rate meant results from the detailed study of human health, development and behaviour were of better quality than similar studies.
In other studies, people who were struggling and had difficult lives dropped out, which meant the results painted a ''rose-tinted'' picture.
Participants kept coming back from all corners of the globe because they believed the research was making a real difference.
''They know that what they are doing matters and they like that. Who wouldn't like that?''
He was also careful to ensure participants were treated with respect.
An example of dedication was a 38-year-old participant who took part despite the fact they were dying of a brain tumour. They took part one last time and died two days later.
