Dr Sandhya Ramrakha, research manager with the Dunedin Multidisciplinary and Development Research Unit – November 2, 2017.
Almost 200 people heard Dr Ramrakha discuss findings of the world-leading Dunedin study, renowned for its breadth, depth and high retention rate of participants.
The study followed the lives of over 1000 babies born in Dunedin’s St Mary’s Hospital in the year from April 1, 1972, and its research findings have influenced and informed policymakers in New Zealand and overseas since that time.
Among its general findings:
- Persistent cannabis use starting in the teens resulted in an average eight point drop in IQ, which was not recovered on stopping its use, and serious gum disease.
- Activation of the 5HTT gene associated with depression and antisocial behaviour only occurred if the child was maltreated. So, she said, it wasn’t a case of genes versus the environment, but genes via the environment.
Effects of childhood self-control:
- Poor self-control from age 3 to 11 (as measured by self, parent and teacher reports, plus clinic staff observation) led to statistically worse substance abuse, health, income, occupational prestige, future planning, criminal and parenting records in adulthood – even controlling for other likely trigger factors.
- Individuals with poor self-control in childhood were also more likely to smoke by 15, drop out of school and have unplanned pregnancies.
- People at the other end of the childhood self-control spectrum were “not very boring, uptight people,” – they also scored 20% higher in satisfaction with their lives.
- What we need, Dr Ramrakha said, are innovative policies that put self-control at centre stage. “It is a skill, it’s something that can be taught. And you don’t have to move it much to make a big difference,” as moving a child even slightly along the self-control curve made a huge difference to all the other life factors in adulthood.
- There are two main windows of opportunity to learn – early childhood and adolescence – though we can extend our self-control throughout life. There are many different methods to suit different people – just google it!
- By age 38, the 22% of study participants at the lowest end of the ‘child self control’ spectrum accounted for 40% of the obesity, 54% of cigarettes smoked, 81% of convictions and 77% had no dad. Risk factors for this group included low self-control, poor socio-economic circumstances, maltreatment in childhood and low IQ.
- Researchers in this study – which won last year’s Prime Minister’s Science Prize – showed that a 45 minute paediatric assessment they had done of each individual at age 3 (including such things as IQ, motor skills, language skills, and self-control) was able to predict 80% of those in this group.
- Dr Ramrakha said the study was not trying to stigmatise people, but identify those who are vulnerable and whose lives would be improved with targeted assistance, especially at a younger age.
- Study participants are now 45 years old and are taking part in the next phase of investigation, which is concentrating on ageing. The use of 18 biomarkers on participants when they were aged 38 showed that although all participants were the same chronological age, their biological age ranged from 28 to 61 “in a lovely bell curve”.
- Why do some age faster than others? This is among the questions Professor Richie Poulton (Study Director) and his team hope to discover answers to over coming years.
Anyone wanting research papers or further information from the Dunedin longitudinal study can contact Jenny McArthur , 03-4798507, or email dmhdru@otago.ac.nz