We live in a decaying age. Young people no longer respect their parents. They are rude and impatient. They frequently inhabit taverns and have no self-control." These words - expressing the all-too-familiar contemporary condemnation of young people - were actually inscribed on a 6,000-year-old Egyptian tomb.

Later, in the fourth century BC, Plato was heard to remark: "What is happening to our young people? They disrespect their elders, they disobey their parents. They ignore the law. They riot in the streets, inflamed with wild notions. Their morals are decaying. What is to become of them?"

And then, a few hundred years later, in AD1274, Peter the Hermit joined the chorus. "The young people of today think of nothing but themselves. They have no reverence for parents or old age. They are impatient of all restraint ... As for the girls, they are forward, immodest and unladylike in speech, behaviour and dress."

Such quotes illustrate what I believe has become a historically nurtured and culturally damaging phenomenon: ephebiphobia - the fear of youth. But today this problem is worse than ever.

We live in an increasingly risk-averse culture, where many children's behaviour is constrained. We raise them and educate them "in captivity" because of our anxieties. We are continually hypervigilant, as our anxieties are fuelled by stories and images of violent and aggressive crimes. And then we label children as troublemakers or failures because, as a society, we often fail to see their potential.

Even little children are now becoming victims of our ephebiphobic culture, as powerless teachers seem helpless in the face of nursery hooligans - paedophobia is born.

As a mother and a specialist in child and adolescent mental health, I despair for today's young people, who are feared because of the actions of a minority population - the violent, aggressive and antisocial; a population that has always existed. We see young people as so pestilent that we create the Mosquito, a device only they can hear, designed to frighten them away.

Our distorted perception of young people creates a self-fulfilling prophecy: why bother to try when you are told that you are a failure? Why bother to strive when your existence is seen as a nuisance?

I am not denying that there are some really destructive children and young people - as there are adults. They are mostly those who exist in deprivation and are anxious and aggressive. They are made to feel worthless and so they become destructive. They are incredibly vulnerable.

However, there are many young people who want to make a go of their lives but are blocked at many turns and so give up. Blocked by an education system that narrows the definition of achievement because it is built around targets and testing, and staffed by creatively compromised and disempowered teachers. Blocked by a higher education system that is mostly riven with elitist and narrowly defined notions of academic competence. Blocked by a society that discriminates against youth and so reduces the participation of upcoming generations in the development of the social and cultural landscape.

How can we turn this around?

Children first become negatively labelled in nurseries and schools, and often these labels stick. We so often forget that children misbehave because they are struggling in a learning environment. Schools need more input from child development specialists, who can support teachers to understand and manage the needs of children they see as "difficult".

The educational culture of targets and testing places enormous pressure on school staff who have to manage large classes of children of mixed abilities, and with a huge diversity of needs. It creates a herd mentality. Little boys, in particular, seem to struggle in the worksheet culture of many classrooms.

Clinically, I see many children with sensory integration difficulties (often wrongly labelled as ADHD - attention-deficit hyperactivity disorder). These children can do well with one-to-one support and directed guidance. Paediatric occupational therapy has shown good outcomes with such children, as does a school-family behavioural approach, underpinned by an understanding of the child's strengths and needs. Sadly, many of these children (mostly boys) get lost in huge classrooms, develop behaviours to compensate for their difficulties, and get labelled as the class clown - or worse.

Schools need support and resources to individualise teaching again. We need to have the courage to see child development from the perspective of difference, not sameness. Outcomes in terms of Sats and league tables show nothing more than a herd approach to attainment, and push the focus away from the individual child.

Children labelled as failures in primary and secondary education have no hope of further or higher education, given the limited and mostly elitist way we assess their abilities.

At Edge Hill University, where I am chancellor, we value personal achievement alongside academic attainment, and this helps many young people to broaden their personal and academic horizons. Our fast-track and fast-forward programmes enable 500 learners a year, of all ages, who do not have A-levels, to realise their potential without incurring any financial cost. The selection process for these unique gateway courses is based on the individuals' potential and motivation, opening career doors that would ordinarily be shut to them.

At Edge Hill, we try to see those that are defensive, underachieving and at times hostile as young people who need the most support - not to be written off - and so we uncover the most extraordinary young people.

My wish would be that those universities that "protect" their reputations via elitist and narrow assessment criteria, which rely on attainment in a traditionalist sense, start to look more broadly at criteria of success that encompass the whole person and not just their grades. Many universities lack robust student diversity and so do not allow themselves to benefit from young people who bring varied life experiences to their student population. If their school was not able to meet the needs of the more complex learner, many of these young people have lost any thought of higher education before they've even made the transition to secondary school.

We are an ephebiphobic society and we should be ashamed of ourselves.

• Professor Tanya Byron will give a lecture, The Trouble with Kids, at Edge Hill University, Ormskirk, on Tuesday 24 March at 6pm. More details: buckleys@edgehill.ac.uk

The misunderstood

Joe White, 16, Shropshire

I've had people cross the road to avoid me. It's worst when you're wearing a hoodie. The problem is that people have read all this bad stuff in newspapers. They focus on the small minority of teenagers who get up to things, and the rest of us are tarred with that brush. It's unfair to label us all like that.

Andy Marlow, 17, Birmingham

I'm a member of the youth parliament, and we're trying to organise an event at the House of Commons. One MP has been really negative about it, saying we're bound to make trouble. Last year, at the same event, the peer who organised it said we were a lot better behaved than a lot of MPs.

Anna Godinho, 16, west London

When you get on public transport, especially if you're in a group, it's like: "Uh-oh! They're going to cause trouble!" But we're just like them: we're using the bus or the train because we want to get somewhere.

Charlie d'Auria, 18, south London

I got on a train with a friend whose dad had bought us first-class tickets. Straight away the guard arrived and was quite rude to us. He just assumed we were somewhere we shouldn't be. He treated us with a total lack of respect.

Daniel Olaiya, 16, Torbay

At the bowling centre where I live they actually have one of those noise-machines, the Mosquito, to stop us from congregating outside. It's like we're as bad as insects and they want to scare us away. We're not taking drugs or drinking, we just want to chat with our mates.

Interviews by Joanna Moorhead