George Monbiot begins his Guardian op-ed this week with this jaw-dropping assertion:

Self-deprecating, too liberal for their own good, today's progressives stand back and watch, hands over their mouths, as the social vivisectionists of the right slice up a living society to see if its component parts can survive in isolation. Tied up in knots of reticence and self-doubt, they will not shout stop.

Has Monbiot been asleep for the past 18 months of deficit-denying, Wall Street Occupying, Murdoch-pieing shenanigans? Has he heard of UK Uncut or 38 Degrees? Did he notice all the strikes and marches in London? Does he, indeed, ever read his own newspaper? His article—titled ‘The right’s stupidity spreads, enabled by a too-polite left’—appeared on the same day as the The Guardian published such opinion pieces as ‘The NHS bill could finish the health service—and Cameron’ (Polly Toynbee) and ‘Why we need more banker bashing’ (Sunny Hundal). This is hardly unrepresentative of the organ’s output.

The issue that the left is “too polite” to mention is an academic study which Monbiot (wrongly) claims to have “revealed that people with conservative beliefs are likely to be of low intelligence.” Have you heard about this well-guarded piece of secret research? Of course you have. Only two days earlier, the reticent and self-doubting Charlie Brooker covered the ‘right-wingers are stupid’ story and proved his point by quoting comments left on The Daily Mail’s website. Guess what? Some of the things people say underneath Daily Mail stories are really stupid! One hopes Brooker waived his fee for this journalistic turkey shoot.

In a classic example of confirmation bias, Monbiot declares the study’s findings to be “embarrassingly robust”. This is not the view of the statistician William M. Briggs, who calls the study “a textbook example of confused data, unrecognized bias, and ignorance of statistics”. The study’s methodology does indeed appear to have been designed with the preferred conclusion in mind and it is not difficult to guess the political persuasion of its authors. Even if the findings were sound, the study would only serve as a reminder of how useless that ridiculously broad and pejorative term “right-winger” is.

Monbiot fails to mention it, but libertarians and free-marketeers do not have a dog in this fight. The study examines homophobia and racism with a selective definition of “conservative ideology” thrown in for good measure. The researchers define right-wing ideologies as “socially conservative and authoritarian”, which rules out Monbiot’s hated libertarians and “neo-liberals” at a stroke. People who agree that “Schools should teach children to obey authority” and “Family life suffers if mum is working full-time” are, by the questionable definition of these researchers, “right-wingers” and they find correlations—though not very strong ones—between these attitudes and weaker cognitive abilities. There are similar correlations with racism and homophobia. It turns out that bigots are not always very intelligent. Who would have thought it?

But Monbiot is not prepared to leave it at that. Although the study clearly relies on a North American view of the political spectrum in which the left is socially liberal and the right is socially conservative, Monbiot cheerfully conflates it with the economic outlook of the British Left and Right. The “Conservative appeal to stupidity”, he says, manifests itself in reforming the benefits system and checking whether people on disability benefit are actually unable to work. But one wonders how many Americans on the left or the right would consider capping benefits at £26,000 ($41,000) a year to be unreasonable, let alone “stupid”.

Much as Monbiot would like to think otherwise, a study of social prejudices tells us nothing about the wisdom of his brand of Malthusian, zero-growth economics. Tax-and-spend leftists and Spirit Level suckers who still cannot grasp the broken window fallacy after 160 years should hesitate before calling people dumb. In 2010, researchers exposed the left’s economic incomprehension when they asked people whether they agreed with statements such as “Restrictions on housing development make housing less affordable”, “A company with the largest market share is a monopoly” and “Free trade leads to unemployment”. They found self-defined Progressives and Liberals to be consistently more ignorant of basic economics than self-defined Libertarians and Conservatives.

The study was, however, criticised for choosing statements designed to trip up left-wingers. When the researchers conducted the experiment again last year, they added statements designed to appeal to the prejudices of the right, such as “Making abortion illegal would increase the number of black-market abortions” and “Legalizing drugs would give more wealth and power to street gangs and organized crime.”  With these new statements included, the differences between political factions evened themselves out somewhat. Progressives still did worse than Libertarians overall, but it was concluded that “all groups do poorly, with each group tending to do relatively poorly on questions challenging its positions”. Regardless of political affiliation, people tend to believe what they want to believe. This is a conclusion that Monbiot should bear in mind before he allows one piece of flawed research to confirm his bias.