In modern life the most improbable and abstract things become quantified. A case in point. The organisers and members of Mensa International believe that rooted deep within every individual brain is a number. For Mensa - that number expresses an Intelligence Quota or IQ. The notion of IQ has, in recent times, seamlessly infiltrated our language becoming a synonym for intelligence more generally. The ability to assess IQ levels is regarded, by Mensa and others, as a genuinely scientific procedure which allows for the cataloguing of 'enlightened' minds.

However it is worth considering that the history of IQ testing is pervaded by a darker and more sinister aspect altogether.

In the late 19th century Cambridge educated statistician Sir Francis Galton, a cousin of Charles Darwin, was to provide the template for IQ measurement. Influenced by his relative's famous theory of natural selection, Galton took strides to create something equally revolutionary but which focussed on the social evolution of human beings; he sought to demonstrate that 'intelligence' was an innate biological category cosseted in the matter of our brains; this, in turn, allowed for the implication that some of us would be born with more of it than others.

Galton's theories provided the thin veneer of pseudo-science necessary to justify an already explicitly racist and imperialist outlook. He has the dubious 'honour' of introducing the term 'eugenics' to the language, and was a pioneer of the notion of heredity intelligence passing down the generations of white Europeans, a passage which, according to him, was interrupted and threatened by the integration of "less intelligent races."

In the American Deep South such a world view was swiftly gobbled up. In 1906 Virginian physician Robert Bennet Bean published an article which claimed to demonstrate the inferiority of black people; this study, and others like it, would provide an impetus to a burgeoning eugenics movement in the US, a movement which would lead to the Immigration Restriction Act of 1924 and the enforced sterilisation of thousands of women, mainly African Americans.

The IQ tests which purported to demonstrate the innate intellectual inferiority of blacks, and other minorities - tests which often yielded results in favour of white Caucasians - were in fact highly deceptive. For as Professor of Social Psychology Richard Nesbit points out, they obscure entirely the role played by social relations. Nesbit draws attention to the fact that a child raised in a well off family can sometimes have, on average, up to a 25 point higher IQ than their counterpart living in poverty. In the US, at a time of apartheid, and indeed in its aftermath, black children had and continue to have far less access to education; they were often unable to refine the skills on which the IQ tests were premised.

Thanks to the work of scientists such as Stephen Jay Gould, who have rigorously exposed IQ testing as 'the mismeasure of man' - those who continue to use IQ tests in order to bolster racist views are almost always the kind of cranks and lunatics you would expect to encounter on the fringes of white supremacy movements. Nevertheless the concept of 'innate intelligence' has itself mutated in order to adapt to a post-apartheid world. It has graduated from an explicitly racial orientation to a subtle and implicit focus on gender and class, acquiring a far more libertarian character in the process.

As an English language tutor I would often have to go to staff meetings to discuss teaching method. I worked for many different institutions but almost all of them placed emphasis on what are called 'multiple-intelligence theories'. These tend to argue that each child is blessed with an innate intelligence - Bob is 'logical', Mandy is 'musical', Paulo is 'spatial' and so on. Now on a certain level this had a progressive character - it wasn't like the original IQ tests which sought to demonstrate that specific ethnic groups were either innately stupid or innately intelligent. Rather 'multiple-intelligence' seeks to show that every child is gifted albeit in different ways. But it does not do away with this aspect of the 'innate' - instead it proliferates it.

And this is the problem. Certainly in the course of a child's development he or she will become better at some things than others. I struggled with history until GCSEs when I had a teacher who really inspired, and suddenly it began to interest me. The crucible of education should imply a living development in which children are experimenting and refining their intellectual makeup - continually developing new abilities and interests while possibly shedding older ones. At six Maria wants to be an artist, by 13 though, she is crazy about being a doctor.

But when one theorises a particular innate disposition, the concrete social circumstances inevitably fade into the background. It is not important that David is in a class chock full of great resources and only three other pupils while Derek learns in a beaten down room alongside 30. What is important it that David's intelligence is 'logical mathematical' while Derek's is 'body-kinesthetic'. The corresponding implication is that if Derek gets a low paid job as a manual labourer and David finds himself in position of power as an MP, they are merely fulfilling some inherent-genetic destiny. The theory of 'multiple-intelligences' is fully imbued with the rationale of the status quo.

When I was a child my mum would help me with my English homework but she was always reluctant when it came to maths. 'I don't have a mathematical mind-set' - she'd say, with a hint of regret. At the time I took this at face value. Some years later the subject of her education came up again. She hadn't chosen to do maths for O-levels, she explained, because a teacher had told her that girls were more suited to home economics. There is a real sadness in that. Intelligence theories don't serve to locate intelligence in our children. They serve to limit it.