Teaching self-control to children as young as three can set them up for healthy, wealthy and crime-free lives, researchers have found.
Physical health, alcohol and drug addictions, personal finances and criminal offending in adulthood can be "significantly predicted" by how a child acts up to 11 years old.
The findings, part of a study of 1000 children born in Dunedin in 1972-73, have been released today by chief science adviser Sir Peter Gluckman.
Study director Richie Poulton said the findings could help explain "the New Zealand paradox" of high teenage injury and death rates in such a peaceful, ethical and developed nation.
He believes they could even account for our high national debt.
"Given New Zealanders' well-publicised appetite for debt and aversion to saving, as well as our unacceptably low levels of impulse control [eg child abuse], speculation about a national lack of self-control seems inevitable."
Children in the Dunedin study who grew up without self-control were significantly more likely to be smokers by age 15, to leave school with no qualifications and to become teenage parents.
These "adolescent risk factors" accounted for about half the variability in adult health, wealth and law-breaking, but even after allowing for these intermediate effects there was still a direct effect of childhood self-control on the lives of the Dunedin-born adults up to 30 years later.
Sir Peter's report was prompted by last year's death of 16-year-old King's College student James Webster after he drank a bottle of vodka at a friend's birthday party.
Sir Peter said last year New Zealand had "an unacceptably high rate of poor outcomes in adolescence" with the developed world's highest teen suicide rate and among the highest rates of teenage risk-taking behaviour such as drunkenness and pregnancy.
He pointed to evidence that children who learnt social skills, emotional control and could persist with difficult tasks in early childhood took fewer risks and so suffered less as teenagers.
Professor Poulton said that for young children self-control meant the ability to control emotions and persevere in the face of challenges.
"If you hold off that chocolate now, in half an hour you can actually have two chocolates, for example," he said.
"There is no time at which you can't be thinking in terms of inculcating or teaching self-control skills. They are skills that you can learn - that's the good thing about it."
The study also found a "gradient" of success with children who had more self-control enjoying more health and wealth in adulthood than others who had even a bit less self-control.
HIPPY TUTORS FIND YOUNG ONES RESPOND
Otara mother Eileen Teina was surprised when her youngest son started offering to help with the cooking before he was old enough to go to school.
At the same age, her older two children, now aged 11 and 12, "were running wild all day".
"They would yell at me. They had no self-control," she said.
But with her third child, Calvin, who turns 6 next month, she learned new techniques through the Home Interaction Programme for Parents and Youngsters (Hippy).
Hippy tutors, who are young mothers doing the same programme in the same community, work through books that teach the mothers how to do simple tasks such as reading with their children from a year before school through the child's first year in school.
Ms Teina admits that when she left school "I kind of went off the tracks - basically, friends wanting to experiment and do stuff every other kid was doing at the time".
"That's the reason I wanted to do this programme. I didn't want my son to go the same way," she said.
"With the Hippy programme, not only does it teach you the basics of learning - and having fun as well. It teaches them how to express how they feel and what they're thinking. It taught him how to ask. It teaches you manners, how to ask the proper way."
The programme even taught Calvin to clean up after he made a mess. And most surprisingly, he wanted to help.
SELF INDULGENCE v DISCIPLINE
* Likely to smoke by 15
* Fewer school qualifications
* Higher risk of teenage pregnancy
* More health and wealth in adulthood than others who had even a bit less self-control.