There are lies, damned lies and statistics, but worse still are maths statistics. They send people mad. Elizabeth Truss, the education minister, sets off next week to see why Chinese pupils are so good at maths: indeed, why even working-class Chinese pupils are better than middle-class British ones. She and her boss, Michael Gove, believe the future of the British economy rests on her findings.

Truss's trip, with loyal headteachers in tow, makes The Hunting of the Snark look like sanity. David Cameron and his colleagues are infatuated with anything to do with China. Now it is education. It so happens that in 2010 researchers from the London Institute of Education reported that Chinese school performance had nothing to do with China. Even in Britain, "Chinese pupils from families in routine and manual jobs perform better than white pupils from managerial and professional backgrounds."

It is maths that has the mesmeric appeal. To Gove and Truss it is virtually a state religion. Captains of industry, titans of science, politicians of all parties, they all take up the cry, declaring maths to hold the secret of the universe. Stuff the little blighters full of maths, they demand, and Britain will again rule the world. Square the hypotenuse, and Johnny Taliban will beg for mercy.

The appeal of school maths to control-minded politicians is obvious: it is easy to test, and thus to measure, unlike vague, slippery humanities. British governments, gripped in the vice of targets, crave quantification. They have thus made what is measurable important, rather than what is important measurable. They are Gradgrind's useful idiots.

How else could they credit the OECD's rubbishy but much publicised Pisa tables, which put China "top" in maths in 2012? For a start, the Chinese figures are not for China at all, but just booming Shanghai. The other top maths countries were also de facto city states, such as Hong Kong and Singapore, shorn of their poorer hinterlands. Truss might as well compare rural China with the cities of London and Westminster.

These global surveys are notoriously unreliable. Barely 15% separates the top 25 Pisa states, meaning that sampling discrepancies can move countries wildly up and down. The Cambridge statistician David Spiegelhalter is splendidly dismissive: "The imputation of plausible values, based on an over-simplistic model and assuming the 'difficulties' are fixed known quantities, will underestimate, to an unknown extent, the appropriate uncertainty in the scores and rankings." I could not put it better.

The maths cult is relentless. The Institute for Fiscal Studies claims that maths achievers "earn 7% more at 30" than others. It does not ask if people who earn more just happen to have been good at maths. Truss too is obsessed. Shortly before the crash in 2008, she wrote that Britain's "world-class mathematicians have aided its ascension as one of the financial capitals of the world". They had elevated British financiers from mere bank lenders to "masters of the universe" through their brilliant derivatives modelling and trading. We needed more of them, she pleaded. In that case, I assume it was being too good at maths that cost Britain the worst recession and the deepest misery since the second world war.

I learned maths. I found it tough and enjoyable. Algebra, trigonometry, differential calculus, logarithms and primes held no mystery, but they were even more pointless than Latin and Greek. Only a handful of my contemporaries went on to use maths afterwards. Our teacher told us it was for "mind training", the last cry of the desperate pedagogue. Hence my delight on reading the words of the great mathematician GH Hardy, that his subject "must be justified as art if it can be justified at all".

I know of no proof of a causal link between maths and national success or happiness. The fact that countries that do badly in Pisa league tables, such as America, Britain and Germany, are neither poor nor specially wretched ought to make statisticians at least pause.

Of course children need to be taught the rudiments of number, proportion and probability, as they do to read and write. But there are few occupations that need maths at the level I studied, and they can learn it as a language skill. I firmly believe all the maths most people use can be found in John Allen Paulos's short classic, Innumeracy. It damns alike those who boast "I was never any good at maths", and those who teach it so badly that millions loathe it.

Government manpower planning rarely works. Margaret Thatcher's government declared that Britain needed more mathematicians and scientists. Universities were starved of money for arts and given double grants for science. Teacher salaries were loaded against humanities. John Major and Tony Blair took up the cry. The BBC went on to broadcast hours of Brian Cox and friends, showing science with a sense of humour, cool clothes and better sex. It was a total failure. Young people voted with their feet for the arts – while the economy boomed.

If British schools are to be slaves to Gove's economic dogma, they should be turning out accountants, lawyers, administrators and salespeople. That is where the money is. Britain needs literate and presentable young people, sensitive to culture and the world around them, skilled in health, entertainment, finance, the law and citizenship. The truth is that Gove, like most of Cameron's ministers, is an old socialist planner at heart.

Nobody has a clue what ought to be taught in schools. Britain's curriculum, like its teaching methods and school year, is stuck in Tom Brown's Schooldays. Confused education ministers default to "What was good enough for me is good enough for them". We should all go back to rote.

I once visited Chinese schools; they were like communist drill halls, factories of pressure, discipline and childhood misery. The ultimate ambition for China's top mathematicians is to flee to America's Silicon Valley, where I gather they are packing their children into progressive Steiner Waldorf schools – as far from Gove's dirigisme as could be imagined.

The wisest comment on all this comes from South Korea's former education minister, Prof JuHo Lee. Looking at the highest youth suicide rate in the world, he declares that "test scores may be important in the age of industrialisation", but that was over. Schools should turn their attention to "creativity and social and emotional capacities". Britain is out of date. The maths lobby's bluff should be called. That is the message for Truss to bring back from the east.