A romantic-sounding notion dating back more than 200 years has it that people in prehistory, such as Native Americans, lived in peace and harmony.

Then "civilization" showed up, sowing violence and discord. Some see this claim as naive. It even has a derisive nickname, the "noble savage myth."

But new research seems to suggest the "myth" contains at least some truth. Researchers examined thousands of Native American skeletons and found that those from after Christopher Columbus landed in the New World showed a rate of traumatic injuries more than 50 percent higher than those from before the Europeans arrived.

"Traumatic injuries do increase really significantly," said Philip L. Walker, an anthropology professor at the University of California at Santa Barbara, who conducted the study with Richard H. Steckel of Ohio State University.

The findings suggest "Native Americans were involved in more violence after the Europeans arrived than before," Walker said. But he emphasized there was also widespread violence before the Europeans came.

Nevertheless, he said, "probably we're just seeing the tip of the iceberg" as far as the difference between violence levels before and after. That's because as many as half of bullet wounds miss the skeleton. Thus, the study couldn't detect much firearm violence, though some tribes wiped each other out using European-supplied guns.

The findings shed light on a controversy that has stirred not only living room discussions, but also an intense, sometimes ugly debate among anthropologists.

It involves two opposing views of human nature: Are we hard-wired for violence, or pushed into it?

Anthropologists who believe the latter seized on the findings as evidence for their view. "What it all says to me is that humans aren't demonic. Human males don't have an ingrained propensity for war. . . . They can learn to be very peaceful, or terribly violent," said R. Brian Ferguson, a professor of anthropology at Rutgers University in Newark. Ferguson contends that before about 10,000 years ago, war was virtually nonexistent. But experts on the opposing side also said the findings fit their views.

"A 50 percent increase is the equivalent of moving from a suburb to the city, in terms of violence," said Charles Stanish, a professor of anthropology at the University of California at Los Angeles. "This shows the Native Americans were like us. Under stress, they fought more."

Both sides called the study, which was presented Friday at the annual meeting of the American Association of Physical Anthropologists in Buffalo, a valuable contribution. "Walker's one of the best. This guy's as solid as a rock," Stanish said.

Walker and colleagues examined the skeletons of 3,375 pre-Columbian and 1,165 post-Columbian Native Americans, from archaeological sites throughout North and Central America.

The North Americans came mostly from the coasts and the Great Lakes region, Walker said.

Pre-Columbian skeletons showed an 11 percent incidence of traumatic injuries, he said, compared with almost 17 percent for the post-Columbians.

Walker said his findings surprised him. "I wasn't really expecting it," he said. Yet it undeniably suggests violence, he added. Most of the increase consisted of head injuries in young males, "which conforms pretty closely to the pattern you see today in homicides."

The researchers defined "traumatic injury" as anything leaving a mark on the skeleton, such as a skull fracture, a healed broken arm, or an embedded arrow point or bullet.

Walker said that although part of the increased injury rate doubtless stems from violence by whites themselves, it probably reflects mostly native-on-native violence. "In a lot of cases, such as in California, there weren't that many Europeans around -- just a few priests, and thousands of Indians," he said.

Walker said the higher injury rate could have many explanations. Increased violence is normally associated with more densely populated, settled life, which Native Americans experienced in modernity, he said. Disease could also touch off war, he said.

"Here in California, there was a lot of inter-village warfare associated with the introduction of European diseases. People would attribute the disease to evil shamanic activity in another village," he said.

Ferguson cited other factors. The Europeans often drew natives into their imperial wars, he said.

"Sometimes, the Europeans would enable someone to pursue a preexisting fight more aggressively, by backing one side," he added. Other times, he said, Europeans got natives to conduct slave raids on one another.

Natives also fought over control of areas around trading outposts, to become middlemen, he said. "Sometimes that was a life-or-death matter, since it meant the difference between who would get guns or not."

Stanish agreed. "Obviously, having an expanding imperial power coming at you is going to exacerbate tensions," he said. "They're pushing you. They're going to push you somewhere -- into other groups."

"You're also going to get competition over access to the Europeans, who are a form of wealth," he added. Native Americans fought over areas rich in fur, which the whites would buy.

Yet Native American warfare was widespread long before that, Stanish said.

The natives' ancient practice of using human scalps as trophies is well documented.

Native Americans before Columbus were probably about as violent as Europeans then, Stanish contended.

Ferguson didn't dispute this; indeed, he said, there was a time of unusually heavy violence among Native Americans before Columbus, around 1325. "There was some of the worst evidence of warfare that we see anywhere in the world anytime," he said.

However, he added, "if you go back a couple of thousand years before that, it's questionable" whether Native Americans warred.

Keith F. Otterbein, an anthropology professor at the State University of New York at Buffalo, said the skeleton findings contribute to a balanced, middle-of-the-road view.

"The folks who are saying there was no early warfare -- they're wrong, too. There is, in fact, a myth of the peaceful savage," he said.

Otterbein said the controversy won't end here; both sides are too ideologically entrenched.

"Underlying the 'noble savage' myth," Stanish said, "is a political agenda by both the far right and far left. The right tries to turn the 'savages' into our little brown brothers, who need to be pulled up. . . . On the left, they have another agenda, that the Western world is bad."