A link between vaccine resistance and childhood adversity has been revealed by recent research from the landmark Dunedin Study.
Photo: Karolina Grabowska from Pexels
The Dunedin Study – which tracks the lives of over 1,000 people born in the early 1970s – is the world's longest-running multidisciplinary human health and development research project.
Time and time again, the study has revealed that adult behaviour is linked to what happened to a person earlier in life, says director Professor Richie Poulton. His researchers thought this might apply to those who are hesitant or resistant to vaccines – and they were proved correct.
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Participants in the Dunedin Study who grew up to be vaccine-resistant adults were subjected to all sorts of adversities in childhood including sexual abuse, parental neglect, isolation and poverty, Professor Poulton tells Susie Ferguson.
Tough childhoods led these people to become mistrustful of authority and highly 'stress-reactive' as adults, he says.
"They learnt really early in life to mistrust others, whether they be individuals or institutions. 'You can't rely upon them' is what they basically learnt. And as they grew up they developed personality characteristics that amplified those very early experiences.
"[These people] saw danger or threat where there essentially was none. And when they react to those threats they tend to overreact. That, of course, places them at more risk for mental health problems."
Professor Richie Poulton Photo: Supplied
The researchers found people who were vaccine-resistant frequently had cognitive difficulties in their early life, too.
"They found it hard to process information, hard to read at school. And certainly, when they hit middle age they were not very deep in their understanding of basic medical issues."
These three factors – childhood adversity, a 'stress-reactive' personality style evolving from that and a lack of understanding of medical matters – combined to drive a person's strong resistance to vaccination.
People who struggle to understand why those who are vaccine-hesitant or resistant appear so intractable and impervious to information can take this finding into account, he says.
"You can see why it's so hard [for these people to shift their mindset] because it's been part of how the people are since their lives began."
"If you or I had gone through those adversities and essentially learnt that the world was a tough and capricious place we might ourselves end up thinking the same way."
New Zealand's vaccine rollout seems to have been so successful in global terms – with 95 percent of the eligible population vaccinated – because the Ministry of Health gradually developed an understanding of these psychological factors, Professor Poulton says
