Here's a question for all you anxious parents out there who are busy wrapping your children in cotton wool this summer the better to protect them from the predatory paedophiles inevitably lurking behind every leylandii hedge.

Let's just suppose, in some sick parallel universe, that you wanted your children to be abducted. Let's imagine that you'd had enough of them and decided that your cunning plan was to chuck them out of the house then sit back and wait for some passing kid-snatcher to run off with them. How long do you think you'd have to wait? Warwick Cairns will tell you. It would take 200,000 years, he says. And then you'd get them back within 24 hours. If you wanted them to be taken for longer you'd need to hang about for around 600,000 years. Because in any one year the average child stands a 0.0005 per cent chance of being abducted by a stranger and a 0.00016 chance of not being recovered alive within 24 hours. And yet, obviously, this is not how most people perceive the risk at all.

This perturbs Cairns, which is why he has written a new book How to Live Dangerously: Why We Should All Stop Worrying and Start Living. It is not only a prolonged, statistically-based plea to stop living in our beige world of risk-minimalisation where conkers and sack races are banned and where children are ferried everywhere in cars. It also concludes that if you really want to be safe, you ought to put yourself in more danger.

That's right. Cairns's book turns commonly held beliefs on their heads and presents them back to the reader so that they say something completely different. So, cycling without a helmet to work is actually safer than driving in a car, he asserts, in the face of British Medical Association figures that show that a cyclist is 11 times more likely to die on the roads than a person travelling by car.

How? Because though cyclists are more likely to die in road accidents than motorists, road accidents account for only 1.4 per cent of all deaths. Whereas heart and lung disease account for more than half of all deaths with heart disease killing a third of us. People who cycle 25 miles a week halve their risk of heart disease so more cyclists lives are extended by exercise than ended by accidents. Actuarial data reveals that for every year of life lost through cycling accidents, 20 are gained.

And cycling without a helmet increases your safety further, he argues, because cyclists who wear helmets tend to feel less vulnerable and thus take more risks. The same applies to drivers. Research shows that motorists, seeing cyclists “protected” by helmets, take less care when passing them: they drive on average 3.35in closer and come within 3ft 23 per cent more often. Indeed, in 1989 when it was made compulsory for children in the back seats of cars to wear seatbelts, the number of children killed and injured in crashes initially went up. Because people thought their kids were now properly protected they took less care and drove faster and more recklessly. There is no shortage, of course, of experts telling us that we are cushioning ourselves and our children too much from the lessons of life that actually protect us.

In his book Paranoid Parenting, the sociologist Professor Frank Furedi describes the culture of fear that has led parents to restrict their children's independent outdoor lives and remarks that in 1971 eight out of ten eight-year-olds were allowed to walk to school alone. Now it is fewer than one in ten. Last month his report Licensed to Hug suggested that adults are now afraid to interact with other people's children because they fear being labelled a paedophile. One quarter of the adult population will need criminal record checks under the new child-protection scheme coming into force next year. He says that the obsession with formal vetting will put children in more danger because no one will use their judgment any more. Cairns, 46, says that it was having children (he has two daughters aged 14 and 10) that first caused him to dwell on the increasing ways that we are raising them in “captivity”.

“People keep saying to me that they can't believe how different their childhoods were to the ones that kids growing up today have,” he says. The best example he has of the shift in parental protectiveness is this: “A man I know told his mum, when he was 8, that he wanted to go to Holland for the day with his friend. So she said ‘OK' and actually saw them off to the station with their ferry tickets and made tea for them when they got back that night.” Can you imagine what would happen if a child did that today? The parent would be arrested for child neglect for a start (and rightly). But the anecdote makes a good point about how our willingness to be outraged has changed. Compare it with what happened when Lenore Skenazy, a journalist in New York, wrote in times2 this year about letting her nine-year-old son make his own way home from Bloomingdales on the subway after he pleaded to be allowed to go home alone. Americans were in uproar and she was branded, absurdly, “America's worst mom”. And yet, as Cairns says, we increasingly want to lock our children indoors where there are actually more hazards, not only from relatives (the majority of child killers are in the family), but from other dangers. Three children a day, for instance, are injured in the home from burns or smoke inhalation, and one dies every ten days. “So, they go out and very rarely indeed, one child of the 12 million [in this country] gets abducted,” he says. “Or they stay in where one child gets burnt to death every ten days.”

His book though is not just about mollycoddling children, it is about the irrationality of many of our fears (you would have to fly on an aeroplane every day for 26,000 years to die in a crash - in the same period you'd have been killed 20 times driving to the airport, he says). Indeed in Freakonomics - the formula by which people will fret about, say, Sars, which will almost certainly never kill them, but be blasé about heart disease, which in one case in three will - is expressed thus: “Risk = hazard + outrage”. Which means even if a hazard is low, the amount of public outrage about it can make it appear high and vice versa.

“You cannot help worrying sometimes,” Cairns says. “When a child goes missing and it's in your face five or six times a day on the news, it is going to have an effect. But I just want to say, ‘look it's not so bad'.” Besides, people need risk in life, he adds. Indeed studies have shown that if children's playgrounds are made too safe and too soft children will go off and find something more dangerous,. They need a challenge. He cites the example of a Norwegian headmaster, Asbjorn Flemmen, who recently designed an edgy adventure playground which would never have passed health and safety laws here. It included a “jungle” area left to go wild where children could hide among potentially hazardous hut-building materials. What happened was that after a while the number of children being injured on the site fell dramatically. “The children, through experiencing danger, and after seeing what happened to people who didn't take enough care, soon came to appreciate their own limitations,” he says.

There are things that Cairns does worry about, such as when his daughters are older and start going out with young lads in cars because the risks there are very real. And he would never in a million years start smoking, considering this an infinitely riskier pastime than his two favourite hobbies skateboarding and downhill mountain biking. “I do it for physical exhilaration,” he says. “I have broken a few bones and been knocked out. But if you confront risk and go in with your eyes open, very often you're safer.”

How to Live Dangerously by Warwick Cairns, Pan Macmillan, £10.99

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