A depute headteacher says: "I'd fight against any simplistic definition of reasons behind a change in children's behaviour because it is an incredibly complex issue. If there is a perceived deterioration in children's behaviour, it is because so many other things have changed too.
"There is a far greater concern today about children's behaviour. In the past it was easier to send children to special or remedial classes. Now we have expectations - and rightly so - that we should raise the attainment of all children. In the past it was easy to write them off.
"Social inclusion is a good thing but there has not been recognition that it comes at a price; you have to resource it in terms of staffing.
"In primary, you can't teach and expect to manage a class of 33 if you have four or five children with hugely distinctive needs.
"Teachers have tended in the past to see children with difficulties as somebody else's problem. They wanted the remedial teacher to take them out of the class. Now they know that caring for these children is part of their job.
"On the other side, there are immense pressures on children today, peer and media pressures from aggressive advertising by multinationals.
"Children are consumers from the time they are conscious. As a result, children of all classes or social groups can be materially spoiled, having TVs, DVDs, CD players and computers in their bedrooms and they have access to violence through the media unsupervised in their rooms. They can watch totally inappropriate material - sex and violence - at a young age and even on teatime TV they watch children swearing at adults or being badly behaved towards them.
"One of the biggest effects is the demise of family life. Parents are working too long hours and juggling too many pressures and the child will go from school to after-school care.
"I feel sorry for children today. They're looking for something from school they never used to. It's called family. And that's across the board socially.
"There's also a huge unrecognised problem for children in family break-ups.
Every school has a significant number of pupils going through a period of anguish which is unrecognised officially. Parents often won't recognise it openly because they feel it reflects badly on them. So school is, or can be, the child's only main support. It's a societal scandal that it goes unrecognised and unacted upon.
"Do you know how it feels to sit with a child who is in the depths of despair because their parents are splitting up?
"You can counsel informally and speak to the parents, who might be refusing to recognise the depth of anguish that's being caused. And you can offer a leaflet.
"I had five children in one class whose parents were splitting up at the same time.
"Often children who behave badly have something at the root of it: family.
"The squeeze on schools is incredible. The curriculum is becoming broader and broader and more welfare responsibilities are being put on schools. The whole personal and social development thing is huge.
"Is it not sad that circle time is such a huge thing for so many children? They need that forum because they don't get it at home."