A few weeks ago in a schoolroom of 12-year-olds, a boy with big ears, a radiant smile and, as it turned out, dyslexia excitedly began asking me questions before the class had even started. They were by far the most interesting I received all day and sparked an idea for my next children's book.

So it's not just children who will forfeit something valuable in the boycott by authors such as Philip Pullman and Anthony Horowitz of the Vetting and Barring Scheme run by the Independent Safeguarding Authority (ISA). And it is not just authors who object to the new laws. There are many part-time and volunteer workers who coach sport, entertain, teach after-school music, drama singing or dance and stage events who will decide to spend their time doing something else because they are insulted by the idea that they must prove to the ISA and the Criminal Records Bureau that they are not a paedophile.

Much will be lost, but that is to be expected given the mood of fear and suspicion that has taken root in our schools over the last decade and is doing so much damage to relations between adults and children, and to the children themselves, who are growing up in a surveillance society. It still seems extraordinary that ContactPoint, the children's database that allows access to the details of every child in England and Wales to hundred of thousands of officials, yet not to parents, came about without any fuss. What were we thinking of to allow the construction of such a pointless and sinister apparatus?

Another part of the great suspicion is that schools have become besotted by biometrics and CCTV systems that enable teachers to monitor pupils through the day and, in some instances watch, them in the changing rooms and classroom. At Notre Dame school in Norwich, they are using CCTV to monitor pupils in the lavatory block.

Nothing is being left to chance. A school in Bedfordshire recently banned parents from attending sports day to guard against paedophiles. The man in charge of the event, Paul Blunt, from the East Bedfordshire Schools Sports Partnership, was quoted as saying: "If we let parents into the school they would have been free to roam the grounds. All unsupervised adults must be kept away from children. An unsavoury character could have come in and we just can't put the children in the event or the students at the host school at risk like that." The result of this freakishly protective attitude is that parents weren't allowed to watch their own child compete in the egg and spoon race. What kind of madness is this?

I'll tell you. It is the madness that suggests authority knows best how to guide and protect the lives of our children and, as in the ContactPoint database, that parents must take second place to the needs of the state's protection. It's a kind of Stalinism that promotes the fear of bogeymen, doubts our worth as parents and demands we must prove ourselves to the state before enjoying the simple - and, yes, innocent - delight of a contact with a child who is not our own.

A moment should occur in every child's life, when he or she meets an adult from outside the family and that adult takes an interest in them as a person and shows the child that they have something to offer. This is an important part of becoming a successful individual and I imagine most people reading this remember with pleasure - retrospective awe, in my case - when someone outside school and the family valued them for what they were. Now these contacts are to be policed with a formal structure of suspicion that implies to the child that every adult who has not been checked is a potential abuser. Philip Pullman last week said of the new law, which he likened to Clause 28: "It seems to be fuelled by the same combination of prurience, sexual fear and cold political calculation."

These impulses in a society are difficult to plumb, but the current fear and suspicion strike me as part of some profound doubt we have about ourselves, which manifests itself in these nightmarish visions of fairy-tale evil as well as a blind faith in technology. Reason and proportion need to play a much greater part in our deliberations about the safety of children than they do at present.

But it is a complex problem. Mistrust is so often the basis of relations between the state and the public under this government that it is unsurprising that the pattern of suspicion is repeated in relations between school authorities and their charges. I have argued that the government's attitude infantilises the public and reduces personal responsibility at the same time as enhancing the power of the state. It seems paradoxical that the process is being mimicked in schools, where the whole point, surely, is to allow children to mature into adults and learn responsibility.

Our aversion to risk plays a part in all this, but it must be said that disproportionate supervision is something that schools have warmed to without much pressure from the public or the government. The walkout by politics students at the Davenant school in Loughton when their headteacher installed a globe camera in the classroom was a sign that school authorities were going too far and students rightly ridiculed his explanation that this was to facilitate teacher training.

The spin involved in introducing such systems is always interesting. Pupils at King Edward VI Five Ways grammar school in Birmingham, for example, have been angered by the introduction of electronic fingerprinting, which was presented to them as an easier way of paying for lunch. It emerged that once the school has captured fingerprints, it will be used for daily registration, which I must say is one of the more chilling developments I have yet come across.

Presumably, police will be given access to the school database on demand, but that is clearly not the only worry. A member of the Welsh Assembly, Mark Isherwood, suggested systems that store fingerprints as unique numbers can be hacked, as the US government's National Science and Technology Council has proved, and the fingerprint retrieved. "In future," he said, "fingerprint templates will be used to authenticate passports and bank accounts. Biometrics are extremely valuable and need to be kept in a secure environment."

The sensible course would be to give pupils a unique number or swipe card, but then that would deprive school authorities of the mild thrill of control that lurks in the decision to install one of these systems.

We place our faith in systems and procedures that - frankly - have not earned it. Last week, a woman who left her four children, the eldest of whom was nine, in a park while she went to a shop found her name had been listed with the Criminal Records Bureau. She had done nothing wrong, was found guilty of no crime, yet the report by police will jeopardise any application she may make for a job working with children or vulnerable people.

Hearsay, rumour and unfounded suspicion are now known in the trade as "soft information" and this will be the currency of the new procedures brought in by the Independent Safeguarding Authority in the autumn with a reminder to all concerned that they have a duty to share information. It is tragic that a body set up following the murder of the two Soham schoolgirls, Holly Wells and Jessica Chapman, will deprive children and adults of so much valuable contact, but the more significant point is the generally toxic - Pullman's word - effect that suspicion has on our society.

"Suspicion," Thomas Paine wrote, "is the companion of all mean souls and the bane of good society."