Behaviour which British schools would regard as bullying can be considered "justified violence" by teachers in some nations, according to a London-based academic.
Professor Peter Smith of Goldsmith's college is due to outline some of the differences in countries' attitudes to bullying at an Organisation for Economic Co-operation and Development conference next week. He said: "In Japan and Korea if an older pupil does something potentially harmful to a younger person, it is often seen as legitimate - providing it is done by an older pupil.
"But in this country we would see an older person being nasty to a younger one as bullying."
Professor Smith said that other differences in bullying included the way Korean children would often gang up as a whole class to socially exclude a single pupil, a practice rarely seen in the UK.
Organisers hope the OECD conference in Norway will lead to international co-operation between bullying experts.