What's your first thought when you hear of a teacher being attacked at school? That the child is 'bad' and needs to be taught a lesson? That it's the parents' fault for not teaching them right from wrong?
Or that the child could be mentally ill and knows no other way of expressing their anguish and pain?
While the first school of thought maybe more popular, increasingly, many education experts are starting to take the second view.
Schools across the UK are facing a tsunami of violence with almost 43% of teachers saying they've dealt with aggressive pupils in the last year alone. While it's easy to blame lax parenting, that alone doesn't explain the huge numbers and ferocity of the attacks.
The fresh figures from the Association of Teachers and Lecturers show almost half of teachers believe violence in schools has worsened in the last two years. Of those who faced physical violence, 76.5% said they had experienced pushing and shoving, 37.4% had dealt with punching, 52.4% had faced kicking, 24.1% had dealt with spitting and 2.2% said that pupils had used a weapon, such as a knife.
Now it's true children learn by example - so their actions in school could well be a refection of how they're treated at home. But if a young child believes pulling a knife on a teacher will help her situation, that's not lax parenting but a symptom of something much more serious.
What's abundantly clear is that the current system isn't working. The last few years have seen major cuts to support systems for abused, disabled and mentally ill children. All too often pupils with severe special needs are pushed into unsuitable schools to save money - and simply cannot cope.
Parents have to fight hard to get children statemented and receive the support they need, against councils unwilling and often unable to provide the extra funds. And if a child's own family is in crisis, there's very little chance they'll even be able to fill in the paperwork.
The result? Ill children unable to cope are thrown into mainstream schools. It's horribly cruel - there's no early intervention to help them, they're written off as stupid or troublemakers, and are condemned to a life without respect or achievement, often before they've left primary school. In a culture where we're promised "every child matters", this is no way for vulnerable youngsters to begin their lives.
If a child feels worthless, neglected or unloved, of course they will react. They are wounded, crying out for attention but have no idea how to ask for it. They will overreact at the slightest provocation - real or imagined - and fight hard to hang onto what little dignity they have.
Often - and especially with hormonal teens - this explodes into anger, violence and troublemaking. But look behind the bravado and you'll find a frightened child trying to put up a shield and make themselves look bigger and tougher to shut out the world.
Blaming a 'lack of boundaries at home' simply doesn't show enough understanding of the problem. We're not talking about children who refuse to go to bed on time or get off the X-Box when their mum asks. This is far deeper than that.
These kids don't have just a lack of boundaries, often they don't even have a stable home. They may not have enough food, their parent may leave them home alone for days on end to drink or take drugs, they could be being abused by family members or strangers brought to their home.
The sheer levels of violence show we're talking about thousands of children growing up without love, without being parented, with no positive home role models and no sense of self worth. Happy, well adjusted, kids do not attack teachers - but tormented and desperately unhappy ones may.
So what can we do to end it? Clearly teacher and pupil safety comes first. Schools must implement policies to remove children who threaten to harm others.
But permanent exclusion from school isn't the answer. It's our duty as a civilized society to understand what is happening to these children, to help them overcome it and to give them the very best chance in life.
We don't want to see a generation written off, facing years of unemployment, abuse or jail. If every child matters, let's do all we can to break the cycle of violence and help these troubled children.
But this isn't a job for already-overworked teachers, these children - and often their parents - need intensive specialist support.
The cost of keeping a prisoner behind bars is £40,000 a year. The cost of the successful new Troubled Families programme averages £5,214 for each intervention. You don't have to be a maths teacher to work out the cost of helping vulnerable young children now is worth every penny - both monetary and human terms.