Disorder rules, OK? According to American book A Perfect Mess, published last week, being too neat and organised is just a waste of time. Not only is an obsession with order inefficient - it also blocks creativity. So let’s give a warm welcome to teetering piles of paper on the desk, a riot of wild plants in the garden and unplanned (but not unthinking) activity in the classroom.

As Einstein, who could be considered the patron saint of randomness, put it: “If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk?” He was famously messy. So was Alexander Fleming. As he pointed out, if he hadn’t left exposed Petri dishes scattered by an open window before going on holiday, he wouldn’t have discovered penicillin.

Even Hollywood actor and governor of California Arnold Schwarzenegger has benefited from mess, say the authors, Eric Abrahamson, professor of management at Columbia Business School, and journalist David H Freedman.

From his random approach to training to his apparently haphazard selection of policies, it’s all worked for him.

Consider the educational practice at a private, early-childhood school in America called the Little Red Wagon. There is no set curriculum. There are no carefully planned projects. The children develop it all themselves as they go along “in a sort of festival of creative mess”. Groups of children are provided with a variety of simple materials - corks, coloured sand, dolls, blocks - the teachers read a story to suggest a particular theme, such as the jungle, and then leave the pupils to play. The grown-ups observe, ask productive questions, offer practical help, take notes and occasionally take a photograph - but they do not direct.

The teachers are usually surprised by what the children do. One boy started pounding on a doll with a block. Instead of telling him off, the teacher expressed interest and the boy explained he needed an injured patient on whom to practise medicine. Soon half the class was involved in running a hospital.

All a bit risky at a time when states have rushed into standardised testing for elementary school pupils, the authors point out. But - you guessed it - ex-pupils score well above average in tests. The book also provides a new take on attention deficit hyperactivity disorder (ADHD) - it can be seen as an attention surplus. With tolerance and encouragement, people with ADHD often turn out to be more creative and productive than others.

A Perfect Mess is an entertaining and convincing attack on conventional wisdom. Read it and you need never again feel guilty about your untidy desk or non-existent lesson plan

A Perfect Mess, The Hidden Benefits Of Disorder, by Eric Abrahamson and David H Freedman, published by Weidenfeld and Nicholson, price pound;12.99