Why do smart people believe stupid things?

The trouble with having above-average intelligence is that by definition you're in a minority. In a democracy, that's not a happy place to be. And it doesn't help that so many smart people seem keen to be part of the majority. What is wrong with them? It's a question that pops up repeatedly in this new collection of essays by the Guardian columnist George Monbiot.

The sub-title of the book is 'Six arguments for global justice', but this seems to be the publisher's attempt to impose coherence on a grab-bag of old essays, as the nature of the six arguments isn't at all clear. A better subtitle would have been, 'Why do smart people believe stupid things?', for on this Monbiot does cast some light.

In the case of scientists, Monbiot suggests - rightly - that a key reason is that many are in the pay of big business. Why else would so many of them talk cobblers about the

planting of commercial GM crops being 'vital' to scientific progress?

Being badly informed is another reason. Monbiot recounts how the academic and eco-warrior David Bellamy came unstuck by foolishly quoting incorrect data about melting glaciers from a dodgy website.

But what about those who want the West to jeopardise its economic future by imposing dramatic cuts on greenhouse gas emissions while hoping diplomacy and cash hand-outs will convince China to follow suit? On this, Monbiot is silent - not least because he's the smart guy suggesting this barking idea.

If there's money to be spent, it must go on finding sustainable technologies that we can sell for profit. Maybe Monbiot can't see this because he's an unreconstructed Lefty hoping environmentalism will trash capitalism. Or maybe it's simply that, like a lot of smart people, Monbiot isn't as smart as he thinks.