Forget information overload. Your first thoughts may lead to your best decisions, writer Malcolm Gladwell tells Shane Hegarty

A book about the brain started, says Malcolm Gladwell, with his hair. It certainly is a striking style, a shaggy Afro somewhat impossible to ignore.

So it proved for the New York police department, who took up a sudden interest in him when they had previously left him well alone. Gladwell has sold almost a million copies of The Tipping Point and is paid handsomely to share his wisdom with business leaders who treat every sigh as sage pronouncement. One day he was stopped by officers on the hunt for a rapist, and they thought he might be the guy. Gladwell was curious to know why.

"I was so struck by the profound difference in the way I was treated when I grew my hair. It was such a trivial and irrelevant thing from my perspective that made such an instant difference in the nature and quality of people's snap judgments about me."

The result was Blink: The Power of Thinking Without Thinking, in which Gladwell examines what it is that feeds human intuition, and the importance the first two seconds of thought can have on a final decision. It does not hold back on its conclusion, giving it away on the dust jacket. "Don't think," it orders. "Blink."

"The idea is really to kind of take our snap judgments seriously," he says. "We know we think this way, but we tend to marginalise them, think they're not important or forget about them.

"What I try to argue is that this kind of thinking is central to the way we try to make sense of the world. Sometimes it's really central in a good way and sometimes in a bad way, and we need to understand that and do a better job of appreciating the difference between good and bad judgments."

He looks at the problems with focus groups and how a few minutes with a couple can reveal if they will eventually divorce. He asks why a range of experts can examine a piece of art and declare it to be a priceless original, only for one person to spot it as a fake within seconds of seeing it. He asks why we are suckered by appearances, such as when the American public saw the tall, handsome Warren Harding, decided he looked utterly presidential and then voted him in to be the worst president (1921-1923) in the country's history.

"I don't really believe in pure intuition any more, I pretty much believe it's all experience-based, with the exception of very rare animal instinct, like if I come up behind you and roar in your ear, you will jump. But all of the interesting and consequential instincts are acquired as a result of experience. And it's much more useful to think of it that way. You only get into trouble if you think it's all innate ability, because then you have people running around saying they should always trust their instincts, which is just the worst possible strategy imaginable."

Yet, he also argues that too much information makes for bad decisions, most notably in a chapter on a war game in which the US military was in meetings while a retired general, hired to make sure his side lay down and played dead, was busy destroying its fleet.

"We have come to fetishise information," Gladwell says. "We have come to wrongly associate the volume of information with the quality of the decisions. Really, the important thing is interpretation of the information. And that interpretation can be frustrated by things like volume. You can overload someone to the point where they can't see the distinctive pattern in something. I don't think we respect that fact enough, we're much too in awe of the idea that the more facts we gather the better the outcome at the other end. That's just not true."

Like The Tipping Point - about how a small trend can become a phenomenon - Blink comprises a series of examples strung into a common theme. And it once again employs Gladwell's entertaining conversational style as he filters the fascinating facts from the academic gloop. It's filled with the idioms that helped make The Tipping Point not just the title of a book but a new addition to the cultural lexicon. He talks about "thin-slicing" and "thick-slicing" and "rapid cognition".

"I've chosen to cultivate that," he admits, "because if you want people to talk about your work, you want to give them tools to talk about it."

The success of The Tipping Point both assured him that there was "the hunger for this kind of writing" but also gave him "carte blanche. I feel like I'd gotten my success out of the way." It helped greatly that a book about phenomena became one itself.

"It was kind of relieving. If you write a book called The Tipping Point and it's about word of mouth, it had better have good word of mouth. If a book about word of mouth only succeeded because of a multi-million dollar ad campaign, it would be embarrassing."

The Jamaican-British 41-year-old has spent recent years as a journalist at New Yorker, where he specialises in writing thoroughly enjoyable articles about apparently prosaic subjects. He recently wrote about why tomato ketchup is so tasty simply because he wanted the challenge of taking a dull subject and making it interesting. He is currently working on a piece about a man trying to make the world's greatest cookie.

"I've always felt that the mundane is more exciting than the exotic and that complex things can have deeper and more interesting parentage than things that are out on the fringes. I'm also interested in the dumb obvious question. Coca-Cola is more interesting to me than some $100 bottle of wine. Coca-Cola has to appeal to 65 per cent of the population; wine only has to appeal to five per cent of the population. Mundane things work within all kinds of constraints that high-end things don't, and I find that notion really quite captivating."

Companies pay him $40,000 a time to come and impart the knowledge, although he refuses to accept that it makes him any kind of business guru.

"I don't like that term, because a guru is someone in the context of business who brings some specific and relevant knowledge to it. When I give a talk somewhere I'm not consulting, I'm just talking about my own ideas and people can use them how they want. So, it's not any different from the act of writing the book. I have an audience for those ideas, and that's a wonderful and gratifying thing. But the word guru I shy away from, because it suggests I do something I don't. I'm just a writer who sometimes talks."

Already, Blink has been leapt on by managers and management consultants and he is quite flattered by that. Yes, the point might be misunderstood and people might suddenly decide to make big decisions based on nothing but blind intuition, but once it leaves his pen, he says, the writing no longer belongs to him.

"That attitude has a cost, which is that people will sometimes take what you've written and distort it. But that's the way of the world."

He doesn't mind admitting that he'd rather write books that change the world than ones that drift by unnoticed. "I do think that this kind of thinking is so central to so many different tasks, that if we can get better at it then it really can make a difference. I didn't say that lightly. I don't think you can read this book and conduct a job interview in the same way as before. It's one of the principal ways in which we discriminate against people, in that small moment in which we decide if we are going to hire them. And if all this book did was encourage people to change the way they interviewed people for jobs, that would change the world. In a small way; but it would."

Blink: The Power of Thinking Without Thinking by Malcolm Gladwell is published by Penguin, £16.99