Governments must act to prevent bullying in schools, education ministers from rich countries were warned last week.
"Bullying must be stopped," Norwegian prime minister Kjell Magne Bondevik told the conference of ministers, officials and academic experts, organised by the Organisation for Economic Co-operation and Development in Stavanger, Norway.
Even in the host country, which has a long tradition of anti-bullying initiatives, research now shows that what goes on in the playground has severe consequences for adult life. A Norwegian report has revealed that suicide linked to bullying occurs more frequently than accidental death in the country's workplaces.
Bondevik and his minister for education, Kristin Clement, urged countries to come up with "co-ordinated and long-term efforts" to eradicate bullying from schools.
Professor Dan Olweus, manager of Norway's Olweus anti-bullying programme, said it had succeeded in reducing incidents in some schools by up to 50 per cent. However, the results are mixed and British experts, Professor Peter Smith of Goldsmiths college, London, and Rob Osborn of the Anti-Bullying Alliance, UK, questioned whether local schemes can transfer to other countries.
"It would be hard to implement Olweus in the UK because it's extremely expensive," said Mr Osborn. "Staff training, peer evaluation, co-operating with a team of experts for 18 months - it would strain resources."
Heinz-Werner Poelchau, an official from the German ministry for school, youth and children, said: "I can see how Norway, a country with little over 800,000 children, can deal with this. But in Germany we just don't have the money to fund such a programme."
Cultural differences even within Europe would make it hard to agree on a common policy, said Rosario Ortega Ruiz, professor of psychology at Cordoba university. "The word 'bullying' doesn't really exist in Spain," she said.
British initiatives were warmly received at the conference. Greg Sampson and Peter Harvey's "Rtime", developed to teach children interpersonal skills, tackle bullying and enhance attainment and citizenship, and championed by Leicestershire educational psychologist Caroline Trimingham, generated a lot of buzz.
Experts called for a rigorous evaluation of anti-bullying programmes to assess their impact on bullying and on children's behaviour and academic performance.
One thing, though, was universally agreed on: the need to tackle bullying quickly and effectively. "We have to start from reception class upwards, making children aware of strategies to combat bullying if we're going to protect the adults of the future," said Mona O'Moore, of the anti-bullying centre at Trinity college, Dublin.