In 1939 the documentary-maker Humphrey Jennings made a short film called Spare Time. It shows the working people of heavy industrial towns such as Sheffield and Pontypridd enjoying themselves between the factory hooter and retiring to bed. It is a cinematic poem about local choirs, pigeon fanciers, kazoo bands, ballroom dancing and cycling out to country pubs. As with all Jennings’s films, Spare Time is intensely lyrical and maybe a bit sentimental. I find it very moving. It evokes in me nostalgia for a time I never lived and which was probably pretty hard for the people the film portrays. The final section, set to the music of a Welsh male-voice choir, never fails to bring a tear to my eye.

It was the initial inspiration for a television programme of the same name I have made with the director Neil Crombie. We wondered what had happened to those old-time pursuits and what we might have lost with them. After work most of us flop in front of the telly, play computer games or surf the internet for an average of four hours a night. Studies keep telling us that we are more depressed than we were half a century ago.

The Jennings film shows my grandparents’ generation bound together in work and play, down the pit and the pub. They were poor by today’s standards but being thrown together, living close to the factories in which they worked and having to make their own entertainment, they were rich in something we often lack today: social capital. Social capital is the collective value of social networks and the spirit of co-operation they engender.

In his book Bowling Alone, a study in the breakdown of the American community, Robert Putnam reports that involvement in organised community groups has halved since the Sixties. He counts the cost of the loss of trust and caring that came with participation in local societies, clubs and political parties. I once asked my grandfather which was the happiest time of his life and he surprised me by saying the war, when he was an auxiliary policeman. Robert Putnam thinks only the moral equivalent of a war will restore the social capital America has lost. My theory is that global warming may supply us all with just that.

In the course of our film research, what we found was disheartening but not without hope. Spare time has become leisure and leisure an industry. The hobbies most beneficial to mental and physical wellbeing seem to be old-school, maybe even a bit nerdy, such as the Sealed Knot, a historical re-enactment society. They are communal, involve learning specialist skills and contribute to one’s sense of identity. Most of these pursuits have declined in popularity; we now seem to prefer leisure activities that are solitary, undemanding and expensive.

Today the words hobbyist and amateur have derogatory overtones. Leisure products are sold to us as if we were joining a high-tech, high adrenalin profession, all sponsors’ logos and promises of performance enhancement. In the age of The X Factor there seems to be this increasingly common idea that everyone has a right to follow their dreams and become a professional star, whether talented or not.

As Simon Cowell will tell you, it is not practical or really desirable for most people to jack in their job and pursue their unrealistic hopes. Better to become an enthusiastic amateur. We are losing sight of the fact that a huge part of the pleasure derived from practising a hobby is because it is just that — a hobby. The pleasure is in the doing, whether we are any good or not.

I have always thought that when someone is concentrating and absorbed in doing something they love, such as a singer in a choir, their face takes on a certain beauty. The psychologist Mihaly Csikszentmihalyi called this state “flow”, perfectly pitched between anxiety and boredom. He thought that when someone was in a state of flow he or she was at their happiest.

I want to celebrate the hobby. I’ve had hobbies all my life. As a child I made model aeroplanes, soldiers, cars, tanks and ships. In my teens and twenties I was a mad keen skateboarder, in my thirties it was mountain-bike racing. I’m a lifelong motorcycle fanatic. Recently I have had an enthusiasm for radio-controlled car racing.

All these have fed at some time into pieces of work and I can trace my creative roots back to happy times spent with an Airfix kit, hallucinating the Battle of Britain, high on glue fumes (how sad I was to hear that the future of Airfix is now in doubt after Humbrol, its parent company, went into administration).

A core thread in my art developed not in the white heat of philosophical debate but in the warm glow of fellow hobbyists. I learned pottery at evening classes among enthusiastic amateurs.

So if you want to live happily and longer, join an organised group and learn to tango, go bird watching, play in a brass band, talk about books, anything — after you have watched my film, of course.

Grayson Perry’s Spare Time is on More 4 on Sept 20 at 9pm