Let teenagers have their kicks. They are only doing what comes naturally

Rear view from a sad teenager girl outside
Teenagers: alittle too much on their minds these days. Photograph: Catchlight Visual Services / Ala/Alamy

British teenagers are an increasingly responsible and sober bunch. Teen pregnancies are at an all-time low, drug-fuelled dance culture is vanishing, careers are planned from a tender age, and preparations are made for a lifetime of tuition fee loan repayments and pension contributions. Most of the evidence shows that today's teenagers are altogether more sensible than their irresponsible, selfish parents ever were.

But where did all the fun go? What about the naive, wide-eyed collision that is supposed to happen when each teenage generation encounters an unprepared world? In other words, I worry that teenagers are becoming prematurely middle aged.

Teenagers are a wonderful human innovation. Although they are often dismissed as a cultural invention of the postwar years, all the evidence suggests otherwise. As Shakespeare and Virgil made clear in their plots, teenagers are not old children or young adults – they are fundamentally different creatures, with a fresh and impetuous approach to the world. Recently, palaeoanthropology has even shown us when teenagers first evolved. Analysis of tooth development in early Homo sapiens has shown that humans started to take more than 10 years to grow up at much the same time that their brain was making its great leap to near-modern size. This might seem too much of a coincidence.

Indeed, brain scans of modern teenagers back this up – they show that during the second decade of life the brain is profoundly restructured into its uniquely complex final form. Admittedly, the brain may exhibit some quirky behaviour during that decade, but by its end teenagers have developed formidable powers of problem-solving, creativity, self-analysis, focus, ambition, communication and social flexibility. Twenty-year-olds are better than 10-year-olds at everything.

So it was the evolution of teenagers that made us human, and do all the wonderful things humans can do, and the same remains true today. Far from being an irritating transitional phase between childhood and adulthood, teenagers represent a life-stage unique to our species and absolutely essential for its success.

All that brain restructuring means teenagers think in a completely different way from adults – a difference that can be frustrating at times, but a difference we should cherish rather than stifle. And there are some particular features of teenage thinking we must nurture if we are to thrive in the future.

One of these is creativity, something teenagers revel in. Although their thought processes may seem disordered to the adult observer, they are especially adept at comparing dissimilar concepts to create new perspectives. Indeed, many geniuses have drawn their initial inspiration from their almost gauche adolescent thoughts. For example, Einstein wondered what it would be like to ride on a light wave when he was 16 and I doubt he could have had such a crude yet brilliant thought at 60.

Also, teenagers, as we all know, tend to take risks. Parents don't like it, and the authorities don't like it, yet teenagers seem driven to do it all the same. Sometimes, terrible things happen as a result of teenage risk-taking, but very often they don't. The human mind did not evolve in a world of speeding cars, sexually transmitted diseases and potent psychoactive chemicals, and it is poorly equipped to cope with them, yet risk-taking still serves an important function. To be successful in life we have to take some risks and adolescence is when we learn what can go wrong, what can go right, and what it feels like to take a risk. Creativity and risk-taking are essential for human success and prosperity. They are not only important in the arts, but are also the key to success in science, business and the development of a civilised society. If we do not encourage our teenagers to behave like – well – teenagers, then the outlook is bleak.

The first assault on normal teenage behaviour was a side-effect of our well-intentioned protective urges. We decided the risks of sex, the risks of drugs and the risks of relationships were so great that we must warn teenagers about them as part of their school education. This approach has yielded some impressive results, reducing teenage pregnancy, STDs and drug use, yet I fear it has focused adolescent minds too much on the downside. Love, sex and the occasional tipple can be positive and enjoyable experiences, and many adults hold fond memories of their illicit adolescent indiscretions.

However, the greatest current threat to healthy teenage irresponsibility is austerity. The global slowdown has hit young adults harder than anyone else and teenagers can see what lies ahead. All too often, they now fear the third decade of their life, rather than look forward to it. Continuous coursework and assessment at school not only wrings the creativity and enthusiasm from them, but also instils a conservatism, too – a belief that adolescence is only about preparing for adulthood.

More and more, young people come to university and prospective employers with thick dossiers of certificates and commendations for the worthy activities with which they have filled their teenage years. We want sparky people with a fascination for how the world works and an ability to balance hard work and fun, but increasingly adolescence is seen as an opportunity to stuff a curriculum vitae. Young people should do things because they enjoy them, not because they fear for their financial future.

I work in a university and it saddens me how quickly the concepts of higher education and long term debt have become inextricably bound together. Young people used to laugh at the square old adults who took out mortgages and planned responsible financial futures, but now they too face that awful fate. We have imposed a terrible efficiency, an inappropriate self-control, on our young people and we simply do not seem to care.

Youth is not about being responsible – it is about being young and all the enticing, overwhelming, delicious things that come with it. Life has an emotional, sensual vividness to it when we're young and this cannot be recaptured later on. Once that is gone it is gone forever and to cloud a young person's experience of it is unforgivable. We are consigning our teenagers to an awful, bland sensibleness. And that is simply not natural.

David Bainbridge is a reproductive biologist at St Catharine's College, Cambridge, and the author of Teenagers – A Natural History (Portobello)