TO 11 Downing Street for the launch of a book by two Conservative MPs, Matthew Hancock, a former adviser to George Osborne, and Nadhim Zahawi, a former pollster for YouGov. (In the interests of openness, I should say that I agreed to read an early draft of the book.) Masters of Nothing taps into modish fields of research, namely behavioural economics, to argue that the financial crash was the result of human irrationality: our misperception of risk, our tendency to favour evidence that confirms our existing biases, our hard-wired desire to go with the crowd. The authors warn that the crash will happen again unless governments find ways of compensating for these foibles through policy.

This is not the only (and certainly not the most famous) book in recent years to wield the findings of behavioural economics, neuroscience and other embryonic disciplines to kill off homo economicus. The intellectual Zeitgeist has been captured by Nassim Nicholas Taleb's Black Swan and Fooled by Randomness, David Brooks's The Social Animal and the ubiquitous Nudge by Cass Sunstein and Richard Thaler.

Almost all of this work is American but its political influence is strongest among parts of the British right. Mr Osborne, who understands the political value of being seen at the vanguard of ideas, gave the opening remarks at the launch. Daniel Finkelstein, the newspaper columnist most plugged-in to senior Tories, followed him. Just a few years ago, the Conservative Party was the political home of classical economics. Since the advent of Thatcherism, Tories had not questioned the power of rational incentives to shape human behaviour; hence their implicit trust in the market. Now, as part of David Cameron's efforts to revive a more Burkean Toryism, one which purportedly "goes with the grain of human nature" instead of expecting messy reality to conform to rigid theory, it is the party where you are most likely to find rationalism's heretics. The road from Keith Joseph to Mr Hancock is a long and winding one.

This political attention has not been welcomed by all of those toiling away at these emerging academic disciplines. Even the best-selling authors who have translated the source material into popular books worry about politicians invoking these ideas in a glib way. For example, some argue that the main insight of all this study is that irrationality actually works; our cognitive biases have survived for millennia for good reason. When Malcolm Gladwell writes that humans often take less than two seconds to make important judgements, such as what to make of a stranger they have just met or whether to buy a product in a shop, his point is that this alacrity can result in better decisions than longer, more deliberative decision-making. Our rush to judgement is not necessarily a human failing but perhaps a uniqely human skill.

Still, politicians are more conversant with human irrationality than most. Their trade is more governed by it than even high finance. The best politicians are not the deepest intellects, but those with the intuition to accept human thought and behaviour as it is, and the skill to shape it to their ends. I can think of at least three human foibles chronicled by behavioural economists that regularly impinge on politics.

First, loss aversion. Studies have supported "prospect theory", the idea that people fear losing what they have more than they desire gains. Following politicians around on the campaign trail during the last general election, it was striking how many relatively well-off voters cited the fear of losing their tax credits (or child benefit, or some other fiscal transfer) as a reason for their wariness of the Tories. A rationalist would have had these voters down as natural Conservatives; people who would vote for the party on the assumption that it was more likely to cut their taxes over time than either Labour or the Liberal Democrats. Instead, the voters valued what they had (even though it was often a fiscal transfer that formed a tiny part of their overall household income) over the prospect of larger gains. A fellow political journalist has a cheeky line about this: Gordon Brown, author of tax credits, understood behavioural economics long before the Tories.

Second, cognitive dissonance. There are any number of examples of this but one stands out in recent years. Focus groups tell the Tories that their idea to raise the threshold of inheritance tax, which changed political history in 2007 by staving off a snap election that the party would probably have lost, is popular with voters. But focus groups tell the Labour Party that attacking this policy as a sop to the rich at a time of austerity also goes down well with voters. The electorate holds two contradictory views about the same issue. The politician's job is to use his own judgement to decide which of the two views is the "real" one, or at least the most politically potent. As it turned out, the Tories hardly mentioned their inheritance tax pledge during the election campaign last year and have made it a lower priority than, for example, raising the threshold at which income tax starts being levied. Confronted with schizophrenic public opinion on one of their totemic ideas, the Tories decided that the electorate's hostility to a give-away for the well-off, rather than the public's enthusiasm for the easing of a "death tax" they regard as unfair, was the real mood of the country. (I suspect they are right.)

Finally, perhaps the most powerful irrational quirk in politics: that Gladwellian "blink test". Politicians, and their suitability for the highest office, are judged by voters very quickly, perhaps instantly. People who work in politics are often the hardest to persuade of this; they are understandably reluctant to acknowledge that the tactics, speeches and campaigns they slave over can do little to improve the fortunes of a candidate who simply fails the blink test. Neil Kinnock was Labour leader for almost a decade, but I suspect his failure to become prime minister was determined very early on in his leadership. Voters simply did not "buy" him as a plausible prime minister. The same was true of William Hague, who led the Tories to a crushing defeat in 2001 that was probably ensured as soon as he got the job four years earlier. There are figures near the top of the current government who believe that the public made their minds up about Ed Miliband, the Labour leader, some time ago. Having looked at gut reactions to him in focus groups and opinion polls, they are convinced that he fails the blink test, and quite badly.

It is tempting to conclude from the blink test that politics is a shallow business in which profoundly important judgements are made with indefensible immediacy. But I return to the earlier defence of irrationality. Is it obvious that these judgements are wrong, or worse than judgements formed after extensive reflection? A deeper look at Mr Hague in his days as Tory leader would have revealed all kinds of credentials for the highest office: high intellect, a record of precocious achievement, the McKinsey management nous, a temperament given to equanimity. But the verdict reached by millions almost impulsively, that he lacked (at least at that time) the judgement, clout and indefinable x-factor of a plausible prime minister, was surely closer to the truth.

Indeed, Mr Gladwell would question whether such rapid judgements are irrational at all. His view is that lots of thinking is squeezed in to the two seconds of a blink decision: immediate observations are cross-referenced with past experience to generate broad inferences. In other words, voters did not simply refuse to vote for Mr Kinnock because of his look, voice and comportment. Instead, they thought that these superficial failings said something worrying about his underlying seriousness and suitability for the premiership. This is not as rigorous a thought process as an extended itemisation of Mr Kinnock's virtues and vices, but the point is that politics is better described as intuitive than shallow.