CLASS differences affect children’s progress long before they start school and have a growing influence as they get older, new research has confirmed.

The gap between children from low-income families and their better-off peers has opened up by the time they are just 22 months old, according to Leon Feinstein, research director at the centre for research on the wider benefits of learning which is based at London’s institute of education. These early differences in attainment are not set in stone, but they can be difficult to overcome later on, he said.

Using data from the 1970 birth cohort survey, Dr Feinstein found that children’s scores in development tests, such as stacking cubes and putting on shoes, are a powerful guide to future performance. Children with scores in the bottom 25 per cent at the age of 22 months are significantly less likely to go on to gain any qualifications than those in the top 25 per cent.

Tests taken at 42 months are an even clearer indicator of future attainment, with more than three times as many children in the top quarter gaining A-level qualifications or above by the age of 26 as those in the bottom quarter.

Some children do manage to overtake those who outperformed them early on.

While almost 40 per cent of the lowest scorers at 22 months were still in the bottom quartile at 42 months, more than 13 per cent had climbed into the top band.

But upward mobility is mainly for children from more privileged backgrounds. The position of children with a low test ranking at 22 months is unlikely to improve much if they also have parents of low socio-economic status (SES). Even if low-SES children do have high early scores, they are likely to lose this advantage over time.

“Low-SES children do not, on average, overcome the hurdle of lower initial attainment, combined with continued low input,” Dr Feinstein writes in the latest issue of CentrePiece, the journal of the Centre for Economic Performance.

“Furthermore, social inequalities appear to dominate the apparent early positive signs of academic ability for most of those low-SES children who do well early on.”

The lesson for policy-makers is that while early intervention through the Sure Start programme is helpful, efforts to tackle inequality must continue after children have started school.

“I don’t think you can get rid of the social-class differential,” Dr Feinstein told The TES. “But you can certainly weaken it, and redistributive measures in terms of schooling are important because at present middle-class children get better schooling.”

These measures might include putting more resources into schools with a high proportion of children on free meals and raising child benefit, especially for younger children.

“There is also an argument that teachers need help in observing the early signs (of potential) and working with the children more closely, so that the system doesn’t exacerbate problems at home and more generally in the environment.”