In 2000, the latest year for which comprehensive data have been assembled, violence among youngsters left 199,000 of them dead, a rate of 9.2 per 100,000, compared to an overall death rate from acts of interpersonal violence of 8.8 per 100,000.

The highest rates of youth violence were uncovered in Africa and Latin America and the lowest in Western Europe and parts of Asia and the Pacific region.

"With the notable exception of the United States," WHO reports, "most countries with youth homicide rates above 10 per 100,000 are either developing countries or countries caught up in the turmoil of social and economic change."

Turmoil in socially advanced, peaceable New Zealand? That remote land might not leap to mind in any discussion of interpersonal violence, but it along with Israel and Nicaragua are cited by WHO as countries with higher than average rates of injury from youthful violence -- between 20 and 40 such cases requiring hospital treatment for every youth murdered.

Killer kids: Some signs of "problem behavior" are spotted in early childhood. This gradually escalates to more "severe forms of aggression" as the problem child enters adolescence and, typically, these continue. Shades of the "wilding" episodes in New York's Central Park that involved pack attacks on women joggers, WHO notes that violence by adolescents often is committed "in the company of a group of friends" seeking excitement.

Blame the media? "On the community and societal levels, there is some evidence to suggest that exposure to media violence produces short-term increases in aggression." However, WHO is quick to add that the evidence is inconclusive when one comes to the impact of the media on assault and murder and other serious violence, and its long-term effects.

The report does not mention scriptwriters' frequent employment of acts of violence against women in movie and television episodes but it says that wife-whacking and in some cases husband-bashing are common to all countries, all cultures "and at every level of society without exception." In no fewer that 48 national surveys, up to 69 percent of women questioned said they had been physically assaulted by an intimate male partner at some point in their lives.

"Most victims of physical aggression are subjected to multiple acts of violence over extended periods of time," says WHO. "They also tend to suffer from more than one type of abuse. For example, a study of 613 abused women in Japan found that less than 10 percent were victims of physical violence alone, while 57 percent had suffered physical, psychological and sexual abuse.

"A study in Mexico found that over half of the women who had been physically assaulted had also been sexually abused by their partners."

What provokes such abusive behavior? Around the world, there is a remarkable causal consistency, according to the UN agency's report. Among the provocations mentioned are "disobeying or arguing with the man, questioning him about money or girlfriends, not having food ready on time, not caring adequately for the children or the home, refusing to have sex, and the man suspecting the woman of infidelity."

For reasons still unclear, low income increases the risk of violence. Perhaps, the report suggests, because of the greater possibility for marital disagreement but also because of "other factors that accompany poverty, such as overcrowding or hopelessness."