If you want to know which children will grow up to be the most successful adults, look at their reading and mathematics scores at Primary 1, a recently published study suggests.
The study, published in the highly regarded journal Psychological Science, draws a strong link between early acquisition of language and numeracy skills and achievements later on in life.
Researchers Stuart Ritchie and Timothy Bates from the University of Edinburgh in Scotland found that a child's mathematics and reading scores at age seven are key indicators of socio-economic status in adulthood.
They established this connection using data from the National Child Development Study, a large, nationally representative study that tracked the progress of more than 17,000 people born in 1958 in England, Scotland and Wales for over half a century to the present day.
Data was collected at several points during the participants' lives, including at ages seven, 11, 16, and 42.
Their families' socio-economic background, as well as their reading and maths skills were recorded when the participants were seven. At age 11, their IQ was measured, and at age 16, they were asked questions that elicited their views on and attitude towards school or work.
When participants were 42, researchers checked how long they had attended school and their socio-economic status at that point - asking about their jobs, how much money they made and the type of home they lived in.
What the researchers found was a strong correlation between reading and maths scores at age seven and socio-economic status 35 years later.
Reading made such a difference that going up just one reading level at age seven was associated with a £5,000 (S$9,600) increase in income at age 42.
The long-term associations held even after the researchers took other common factors into account.
The researchers concluded that basic childhood skills - literacy and numeracy - proved important throughout life, independent of how smart you are, how long you stay in school, or the social class you started off in.
Achievement in mathematics and reading was also significantly associated with intelligence scores, academic motivation and duration of education.
The results have drawn the attention of educationists and policymakers in Britain, Europe and the United States due to the size of the study and the strong correlations made.
The Edinburgh University study provides strong backing to several other smaller studies in the US and Britain that show how success in later life is built up from a very early age - even before a child begins formal schooling.
Various studies in the US, for example, showed a marked contrast in the range of vocabulary of children from different backgrounds at age three and how that was directly linked to achievement in school later.
What can Singapore educationists and policymakers take away from the Edinburgh University study and others that have similar findings?
First, it affirms the Education Ministry's efforts to provide learning support programmes to shore up the mathematics and reading skills of primary and secondary school students who lag behind.
For several years, the programmes were offered at Primary 1 and 2 levels but earlier this year, the ministry announced that those struggling with mathematics and English will get help to catch up and build a strong learning foundation throughout their primary and secondary school years.
They will also receive closer attention in small groups, through extra coaching by specially trained teachers.
For children in pre-school, there is a programme to help those struggling with their reading at Kindergarten 2 level.
The NTUC, a major childcare operator, also has in place a reading programme for children from nursery years.
These efforts are a step in the right direction.
While several studies support the fact that achievement gaps start early on, not many have attempted to look at whether intervention or remedial programmes can help close the gap.
The ministry's own data suggests that the learning support programmes which used to be provided at Primary 1 and 2 did help level up the maths and English skills of children.
So while it is worthwhile continuing with such levelling up efforts, the results must be studied to see what more can be done.
Some recent research in the US, for example, suggests that rather than remedial maths or English programmes, it may be more useful to develop skills like perseverance, grit, optimism, conscientiousness and self-control in children lagging behind academically. Emerging research suggests that these qualities also play a big part in determining success in later life.
The results of the Edinburgh University study also make the case to extend existing reading programmes to more kindergartens and childcare centres and to start them much earlier, when children start nursery classes.
A big hurdle would be finding pre-school educators who can do reading intervention programmes.
One idea that might work is for the authorities to look into running training programmes to nurture licensed literacy or reading specialists, as is done in the US.
No doubt all this will mean a big commitment of money and resources.
But it will be well worth it if the result of levelling the playing field for disadvantaged children gets them off to a good start in life.