For many years, psychiatrists have known that teen suicides sometimes occur in local clusters, as news that one child has killed himself reaches other desperate adolescents with the mirage of a way out.
Now, as Americans grapple with yet another case of a teen-age boy turning a small-arms arsenal on his schoolmates, some fear that spectacular school violence might be spreading from state to state through the media like some fatal virus.
"How does a 15-year-old reach the point where he can do something like this?" asked John J. Gibbons, director of the University of Maryland's post-traumatic stress syndrome clinic for children and adolescents. "Troubled kids see and hear something like this and see it as a solution. Historically, a cluster of suicides was in one community. Now, with the media coverage, everyone watches these shootings on TV, even if they happen all the way across the country."
"There's a contagion effect," agreed David G. Fassler, a Vermont psychiatrist and author on childhood depression. "The media are a powerful tool."
The ambulances had not yet carried the dead and wounded from a Springfield, Ore., high school cafeteria Thursday when the news flashed across the country and the collective quest for an explanation began.
As was the case with heavily publicized school shootings in small-town America since October -- in places including Pearl, Miss.; West Paducah, Ky.; Jonesboro, Ark.; Edinboro, Pa. -- there was no shortage of opinions on what might have driven Kip Kinkel allegedly to kill his parents before gunning down classmates.
It's the guns, stupid, 192 million of them in private hands, said gun-control advocates. It's not guns, said the National Rifle Association, whose "Eddie Eagle" program teaches even toddlers about firearms: It's lax enforcement of laws on the books. What was Kinkel doing free, NRA officials asked, the day after his arrest on a weapons charge?
'Social toxicity' blamed
Psychiatrists spoke of the "stunted moral development" of children exposed to violence in the home and on video screens. Mental health advocates said managed care has made it harder to get disturbed youths into psychiatric treatment.
Sociologists speculated about overworked parents and schools with too few counselors. Media critics said sensational coverage of violent crime has migrated from local television to national networks.
James Garbarino, director of the Family Life Development Center at Cornell University, said many such factors have combined to produce "social toxicity," an accumulation of stresses vulnerable teen-agers cannot handle. Like many social scientists, he borrows the language of public health.
"Epidemics first take root in the most vulnerable part of the population," said Garbarino, who has studied children in killing zones from Cambodia to the streets of Chicago. "This socially toxic environment is most intense in poor city neighborhoods, but now it's spreading across the country."
Garbarino blames youth violence on familiar toxins: violent imagery in entertainment, even for the youngest children; a sharp decline in time parents spend with children, and a huge supply of semiautomatic guns.
Talking about television with a group of suburban Chicago eight-year-olds, Garbarino was struck that they spoke of the gentle "Mister Rogers' Neighborhood" as "what they used to watch." What they watch now, they told him, is "Beavis and Butthead."
The average child may pass unscathed through the ocean of coarse, retributive behavior in popular culture. But for psychologically vulnerable children -- for those who are abused or clinically depressed, whom no adult helps to sort fantasy from reality -- the culture can be dangerously disorienting, he said.
Children can become stuck in the "vendetta stage" of moral development, with no sense of empathy or compassion, only a driving need to avenge whatever injustice they feel they have suffered.
"Then, on top of everything else, you add guns," Garbarino says. "And we see what happens."
But some experts warn that what is happening is not yet statistically established, and the rash of shootings does not necessarily mean a reversal of a recent decline in the youth homicide rate.
The rate of homicides committed by people under 18 began climbing in the mid-1980s before peaking in 1994 and declining slightly in 1995 and 1996, according to Eric Lotke, an attorney who has studied youth homicide for the National Center on Institutions and Alternatives, a corrections reform group outside Washington.
Gun murders were responsible for the entire increase, which coincided with the crack cocaine explosion in major cities. Lotke found that four cities -- Los Angeles, New York, Chicago and Detroit -- accounted for 30 percent of juvenile homicide arrests in 1994, though they were home to only 5 percent of the juvenile population.