Education 29 November 2012 How knowledge makes you stupid Martha Gill's Irrational Animals column. Print HTML When you’re trying to express a really interesting idea you've just had, perhaps a way to solve all war, or what if this universe, is like, an atom inside another universe? - there’s nothing more annoying than coming across an expert in the field. Their voice turns calm, authoritative, slightly nasal, and they immediately dismiss your thought. "Oh that's blablabla-ism", they say or "I've watched Men in Black too". But then it’s always impossible to listen to other people when you've studied the subject they're talking about. George Eliot puts it best in Middlemarch when she describes conversations between a young woman and her learned husband, Mr Casaubon: “If she spoke with any keenness of interest to Mr Casaubon, he heard her with an air of patience . . . and sometimes mentioned curtly what ancient sects or personages had held similar ideas, as if there were too much of that sort in stock already; at other times he would inform her that she was mistaken, and reassert what her remark had questioned.” Shock of the new Mr Casaubon is not an attractive character but his attitude is partly the result of his expertise. He found his way around these subjects years ago, working hard to get patterns from the mess, and the lines have now hardened, permanently. It happens to us all though - even taxi drivers, and in their case there's neural evidence. You can track distinctive changes in a cabbie's brain after he gets “The Knowledge” –a working memory of the entire map of London – which expands his hippocampi (spatial areas). But the expertise comes at a cost - he finds it much harder to imagine alternative ways around the city. This was shown up in a fairly recent experiment by the psychologists Katherine Woollett and Eleanor Maguire, who performed memory tests on a group of London taxi drivers and found they struggled to learn new routes in areas they knew well. The researchers suspected that The Knowledge, which had enlarged and spread one section of the hippocampus out into other brain areas, was getting in the way making new memories. Once we make our own maps, it seems, they are strangely inflexible. But it's not just spatial knowledge that does this. Accountants find it harder than amateurs to apply new information they have just read to the world of business; expert bridge players are less likely to adapt to new versions of the game. A recent study found that although doctors are more accurate at diagnosis, they are worse than third-year interns at remembering what information it was that they used. We need experts but there is a trade-off in creative thinking. Little wonder that innovations most often happen at the intersection of two fields of expertise. It’s not due to the combination of knowledge, but to bright people crossing into areas they are not familiar with. › The problem Leveson can't solve: we want newspapers to lie to us Photograph: Getty Images Martha Gill writes the weekly Irrational Animals column. You can follow her on Twitter here: @Martha_Gill. From only £1 per week Subscribe This article first appeared in the 03 December 2012 issue of the New Statesman, The family in peril More Related articles Why have men become so lonely – and how does it affect their health? Connected - to save time, money and lives Can Trident be hacked?