The Dunedin Multidisciplinary Health and Development Study found that self-control in childhood predicts health and wealth in adulthood:
The Dunedin Study is the brainchild of Terrie Moffit and Avshalom Caspi, a husband and wife team who work at Duke University and King’s College London. Way back in 1975, the duo recruited 1037 children who were born in Dunedin, New Zealand between April 1972 and March 1973. Moffit and Caspi became their occasional companions through most of their lives, up till the age of 32. At 11 separate points, the duo measured the recruits’ health, wealth and more. And amazingly for a study of this sort, 1014 of the children are still alive and involved.
Thanks to their unique study, Moffit and Caspi have found that children who show high levels of self-control within their first decade of life do better in adulthood. Even after accounting for things like intelligence and social class, those who had a tighter grip on their behaviour as children are now in better health as adults. They’re also less likely to be abusing drugs, have a criminal record, or suffer from financial problems.
Moffit and Caspi assessed the children’s self-control at the ages of 3, 5, 7, 9 and 11, by looking at their hyperactivity, attention, impulsiveness, aggression, and more. The children did the same evaluations, as did their parents and teachers. All the scores were a good fit for one another, so Moffit and Caspi combined these numbers into a single measure of childhood self-control. Finally, they adjusted the value according to the volunteers’ family background and IQ.
This childhood score proved to be a portent of things to come. Children with lower scores (poorer self-control) had poorer health at the age of 32. Their lungs didn’t perform as well. They were more likely to have gum disease, be overweight, or depend on drugs like tobacco, alcohol or cannabis. Among those with the highest levels of self-control, 11% had multiple health problems, compared to 27% of those with the lowest levels (see graph below).
Those with poorer self-control were also more likely to run into financial or social problems. As teenagers, they were more likely to start smoking, leave school with no qualifications, or have unplanned pregnancies. As adults, they had more credit problems and troubles with money, and fewer tangible assets like a home, savings or a pension. They were more likely to have been convicted of a crime, and their own children were more likely to be raised in a single-parent household. And in fact, their childhood self-control was a better predictor of these financial worries than either their IQs or social backgrounds.