Mr Carnochan said there has been no reduction in violent crime

Det Chf Supt John Carnochan said early-years intervention was especially important in tackling knife crime.

He said a balanced approach investing in teachers, social workers and health visitors would be more important than increased policing alone.

Mr Carnochan urged parents to teach children that violence is preventable rather than a fact of life.

Speaking on BBC Radio Scotland, the head of Scotland's Violence Reduction Unit (VRU) said there had been no sustainable reduction in violent crime.

He said: "What we are looking at now is the evidence and research that indicates that sometimes the skills that you lack that lead to you being violent when you grow older, those are learned within the first three years of your life.

"If there is aggression and shouting and tempers and that is how you resolve problems then that is how babies will learn.

Knife amnesty

"When they grow up those are embedded and that is how they deal with the rest of the society and it's very difficult to break that later on.

"It's not about bad parenting or teaching people to be parents - it's about supporting people in a very very difficult job."

Mr Carnochan's comments came as the VRU, based at Strathclyde Police, launched a new campaign.

It will be distributing leaflets on good parenting to every primary school in Scotland.

Mr Carnochan said advice should be given to parents throughout their children's lives, not just in the few weeks after birth and at the start of school.

He added: "We do need sufficient police officers on the street to contain and manage what is already there.

"But if you want change and to bring about a sustained reduction in violence for future generations in Scotland and make Scotland a safer places for the generation to come then you need to invest in early years education."

The VRU was set up by Strathclyde Police in 2005 to tackle violent behaviour in Glasgow and expanded last year to cover the whole of Scotland.