A leaked policy document from Michael Gove's top adviser, Dominic Cummings, shows the vision underpinning educational policy in England. The claim that intelligence is mainly inherited attracted most attention, and is used to justify closing hundreds of Sure Start children's centres for the most disadvantaged.

According to Cummings, these parents are poor because they are stupid, and pass on stupidity genes to their children, so it is futile to provide nurseries.

Cummings's 240-page rant is about much more than IQ. It is wide-ranging and incoherent, but the connecting threads are key. It regards inequality as inevitable. It shows a deep anxiety about the state of the world economy: the solution lies in finding an elite of geniuses who can save it. The world is in crisis but the solution offered is no more rational than the crude sci-fi plots of films like Ender's Game - the search for a boy genius to stop the aliens.

Cummings is obsessed with identifying the top-scoring one in 10,000 children and supercharging their education. He presents a reading list for these future supermen (and perhaps superwomen): their education will consist of advanced maths and physics; genetics-based brain theories; economics; and military strategy.

Cummings claims teachers in state schools are generally mediocre. Teacher training is pointless - just give heads greater powers to sack. His favourite philosopher, naturally, is Nietzsche, whose dream of creating a superman inspired Hitler. Among Greek philosophers, he rejects Socrates in favour of his opponent Callicles: "The superior man, he 'whose nature is equal to it', should trample the inferior... and vent on the world his wantonness, lack of discipline, and freedom... [which] are excellence and happiness." This is definitely the philosophy of the present government.

The belief that intelligence is mainly genetic has long been used to justify inequality. Around 1920 the US's leading expert Goddard explained to his students, "Workmen may have a ten-year intelligence while you have a 20. To demand for him such a home as you enjoy is... absurd... How can there be social equality with this wide range of mental capacity?"

In Britain IQ tests were used for half a century to justify a cheap and limited education for most manual workers' children. IQ scores were intended to be a fixed measure of "inherited intelligence". This has long been untenable; the measured IQ of entire populations has changed radically due to social change and educational improvement. Someone who scores average now would have counted as very intelligent 30 years earlier.

The attempt to isolate an innate core of intelligence from the complexity of upbringing and experience has led to pseudo-science and even fraud, and researchers in "Behavioural Genetics" seem predisposed to believe that ability is overwhelmingly genetic.

The studies that supposedly justified this outlook were based on identical twins separated by adoption. In theory, they have the same genes but a full range of different environments. But the extent of separation was generally exaggerated. In nearly half the cases in one of the largest modern studies, based in Sweden, adoption was by close relatives: typically one twin stayed with its mother while the other lived with grandparents or the mother's sister. The best known American study is based on twins who volunteered precisely because they felt remarkably alike. Twins were often in close contact for years, but the researchers resisted opening up their data to scrutiny.

Even if twins never meet, they can still share similar environments: the same sex and age, attending schools run along similar lines, current trends in fashion and music, etc. The adoption process ensures that prospective parents are reasonably well off, quite well educated, and likely to be caring parents. All of this weights the maths and makes the inherited aspect seem much bigger.

Even so, the researchers constantly shift their ground because the data doesn't fit. Cummings's favourite, London-based Robert Plomin, found that heritability appears to increase over the years, suggesting environment, not genetics. Plomin also reaches the opposite conclusion, claiming it results from people who are genetically clever gravitating towards clever things. He is forced to redefine IQ as an "appetite", not an "aptitude".

Plomin has been predicting for 20 years that we are on the edge of a major breakthrough, and about to find the genes responsible for intelligence, aggression, schizophrenia, ADHD, homosexuality and dyslexia. They are still elusive. Now the experts are suggesting it isn't a single gene but hundreds, each with a tiny effect.

Even the staunchest believers concede that there is a serious gap between what tests measure and the common "general intelligence" they claim is genetic. This highly abstract "general intelligence" is different from ability in school subjects, let alone real activities (maths is closest, because it uses a similar abstract reasoning). They admit that many other factors affect academic achievement and success in life.

So too does Gove's adviser Dominic Cummings. He argues that nurseries don't raise achievement, but we need a programme to increase children's "self-control" so that they won't grow up poor, addicted or criminal! Boot camps for babies next?

This article draws on the following critiques of recent Behaviour Genetics research:

Jay Joseph, Separated Twins and the Genetics of Personality Differences: A Critique, and The Crumbling Pillars Of Behavioral Genetics.

Leon J. Kamin, Twin Studies in Behavioral Reasearch: A Skeptical View.

To read more on this issue, we recommend the following books available from Bookmarks, the Socialist Bookshop:

Stephen Jay Gould: The Mismeasure of Man

Stephen Rose, R Lewontin and Leon Kamin: Not in our Genes - Biology, Ideology and Human Nature

Clyde Chitty: Eugenics, Race and Intelligence in Education.