Civitas has just published an interesting book called The Ins and Outs of Selective Secondary Schools. Edited by Anastasia de Waal, it’s a collection of essays by the usual suspects in the never-ending argument about grammar schools.

De Waal points out that the two sides have more in common than you’d think. In particular, they share a common goal, which is to sever the link between a child’s socio-economic status and attainment. In 2009, according to the OECD, the variance in the scores of British children in the Pisa international tests in maths, reading and science that could be explained by their backgrounds was 13.8 per cent. By this measure, the best-performing region in the world is Macau (2 per cent) and the worst is Peru (27.5 per cent). Britain is close to the OECD average of 14 per cent.

As you’d expect, those who believe in school selection, such as the Conservative MP Graham Brady, argue that clever children from poor families are likely to do better at grammars than comprehensives. Exhibit A in the case for the defence is the dominance of the professions by the products of independent schools, something that wasn’t true before Tony Crosland set out ‘to destroy every fucking grammar school in England’. In response, Fiona Millar and others point out that the number of working-class children at grammars rarely climbed above the 15 per cent mark, even in their heyday, and that the proportion of children on free school meals in the 164 that remain is just 2 per cent. Today, the main beneficiaries of selective education are still the middle classes.

It’s easy to rebut this argument. A majority Conservative government could make it a condition of allowing an existing grammar to expand — or a new one to be set up — that it set aside some places for children on free school meals. Millar also argues that the 11-plus isn’t a true intelligence test — private tutors etc., etc. — and that intelligence isn’t fixed at 11, but continues to develop in adolescence. It is easy to deal with these objections. Design a better test and allow for more movement in and out of selective schools as children mature.

A stronger argument against grammars is that the gains made by the children who benefit in a two-tier system are offset by the losses inflicted on the ones left behind. Failing the 11-plus can leave you with a lifelong inferiority complex, as John Prescott can testify, and children at secondary moderns gets poorer GCSE results on average than children at comprehensives. Against this, defenders point out that it’s not just the recipients of a selective education who benefit. Sir Paul Nurse, the Nobel Prize-winning president of the Royal Society, has made a succession of discoveries that may lead to a cure for cancer. Would he have gone down the same path if he hadn’t attended Harrow County Grammar School? The more deeply I delve into this discussion, the harder I find it to take sides. But the argument that troubles me most is one that applies to both camps. Suppose we invent a new type of school that meets the objective of nearly everyone in this debate, namely, it severs the link between background and achievement? If we succeed in neutralising all the environmental factors that go hand-in-hand with socio-economic status — postcode, diet, parental engagement etc — what are we left with? The answer is a meritocratic school in which achievement is solely the product of IQ and effort.

The trouble is that IQ and an aptitude for hard work are largely inherited characteristics. Why is a school in which success is dictated by a child’s genes fairer than one in which it’s dictated by socio-economic status? More importantly, there’s quite a lot of evidence that children of intelligent, hardworking parents are likely to be smart and industrious, a correlation that’s becoming stronger as university graduates engage in ‘assortative mating’. (People with similar genotypes pairing up with each other.) This was the shortcoming of meritocratic societies that my father drew attention to in his book on the subject — once assortative mating kicks in, social mobility grinds to a halt. All meritocracy succeeds in doing is replacing one hereditary elite with another. Why, then, is it desirable?

Instinctively, I like the idea of this new type of school and I’ve spent the past six years trying to invent it. But I still haven’t answered the question posed by my father.