If you have never heard of biophilia, you might think it is something sordid involving sex and algae. Not the sort of nonsense Annabel Goldie, the Scottish Conservative leader, would get mixed up in. But biophilia is, in fact, harmless, even healthy. It is the theory advanced by Edward O Wilson, one of America’s foremost evolutionary biologists, that suggests we are all naturally drawn to living things.

As a species, humans have an antipathy to the inanimate; the tarmac, concrete and glass that most of us live around. We want life in all its complex, biological glory: this is why children, being more instinctive than adults, want to climb trees, paddle in rivers and pull up rocks to watch the bugs swarm beneath.

Those brought up to enjoy the outdoors know this without being told. Many urban children are not so fortunate, which is why the Tories last week proposed a £10m fund to ensure every adolescent in Scotland gets a week of outdoor adventure before the end of their schooling. The nationalist government look set to take them up on it, and the Liberal Democrats have been quick to claim the credit — it was in their election manifesto last year. A good idea is a good idea.

You might wonder why nobody is worrying about the expense, when we are closing village schools, need to start replacing older teachers approaching retirement and reduce class sizes. But outdoor education pays for itself by saving money in health spending, preventing criminal damage and creating happier, more productive citizens.

Can a week swinging from ropes or splashing about in a kayak really make that much difference? Evidence suggests it can be life-transforming. It is no real surprise that the Tories — not known for advocating measures that bump up public spending — are so enthusiastic. Many of their children will have benefited from the Duke of Edinburgh’s award, which involves a large element of adventure. The scheme is now offered by many state schools, but it remains voluntary — a key part of its philosophy. An additional scheme covering all children would fill a gap.

Wilson, who is a professor at Harvard University, argues that since human beings have spent most of their existence on earth living close to nature — towns are an invention of the last few hundred years — the desire for green space is written into our DNA. Certainly there is abundant proof that being deprived of an open sky makes us all a bit poorly. Mind, the mental health charity, recently recommended that we invest more in “ecotherapy” as an alternative to anti-depressant drugs. Research by the University of Essex and Mind showed 71% of mentally ill people felt much better after a country walk, and 90% had improved self-esteem. Less than half of those surveyed, just 45%, felt a similar sense of wellbeing after strolling through a shopping centre. The healing benefits of being outdoors are already recognised in other countries. Holland uses several hundred farms for therapy in its public health service, while the Wilderness Act of 1964 in the US preserved vast, natural spaces for the benefit of citizens.

America is particularly aware of what this can offer the young. The University of Illinois conducted research on children diagnosed with attention deficit hyperactivity disorder and found their symptoms much reduced when they were allowed to run around in green spaces. This wasn’t simply a matter of letting off steam. A control group exercising indoors also showed an improvement, but not nearly as much as those who felt the grass beneath their feet.

Not so long ago, play meant exploring the natural world. You can do stuff in the country that would constitute vandalism in a town. Damming streams, rolling through heather, digging trenches, carving your name on a tree stump. This is unstructured play: freedom, in other words. Climbing trees, leaving one’s mark in the sand, throwing a stone into a gorge — this behaviour cannot be replicated in urban places without causing disruption and destruction. But it is a normal childhood impulse to change your environment by force — think of the toddler joyfully smashing a tower of wooden blocks with his little fist.

Running wild in the woods will improve fitness, tackle childhood obesity and teach children to care about their environment. But there are other, more subtle educational benefits. It is believed being outside creates a sense of wonder and stimulates the imagination. It fosters a sense of autonomy and independence while also combating stress.

Computer games and television may increase cognitive capacity and sharpen mental reflexes, but virtual stimulation, while valuable and unfairly maligned, cannot replace the uncomplicated pleasure of living, being and doing. The decline in this sort of play has lead to a sort of extinction of experience in our information-rich society. There’s little opportunity for action.

Kurt Hahn, the founder of Gordonstoun School in Morayshire and father of the Outward Bound movement recognised this 60 years ago. He developed Outward Bound to help young merchant seamen during the second world war, when it was noticed they had poorer survival skills than their older colleagues when a torpedo forced the crews into lifeboats. Hahn knew the younger sailors lacked the practical skills that would give them confidence. Outward Bound and the Duke of Edinburgh’s award strive to give teenagers “mini life experiences” to build self-belief.

Hahn believed that the worlds of thought and action needed to be brought together because we had, even then, become a society of spectators. His motto, “There is more in you than you think”, was directly addressed to young people.

America uses Outward Bound to address delinquency. So do we, but selling that concept has been more difficult here, with tabloids likely to denounce it as a jolly for yobs. But testimonials from troubled teenagers who have done such courses suggest their lives have been turned around as they discover abilities that were unrealised — just as Hahn promised.

A week’s outdoor adventure training should only be the beginning. To create a sense of wonder and wellbeing, access to Scotland’s countryside should start in nursery and continue throughout school. If all children discover more in themselves, then the nation’s prospects get an injection of fresh air.

Times Recommends

• Please help: maimed children of war want their lives back
• Unlocking the cruellest prison
• Prince Charles named in £81m court battle