"We know there were a lot of deer at the time, and deer antlers were used as picks, but it is also possible that they were used as a weapon," Schulting said.
Projectiles such as slingshots and arrows may also have been used, and some of the skulls even had injuries with an axe-shaped outline.
Most fractures were on the left side of the head, suggesting a face-to-face confrontation.
"It is the classic situation of two people, both right-handed, having a fight," Schulting said.
The researchers think that most of the conflicts would have been local scraps and regional clashes rather than countrywide battles.
Fabian Kanz, of the Austrian Archaeological Institute in Vienna, agrees with this interpretation.
"When people started to farm and make settlements, there must have been lots of conflict between settlers and local tribes," he said.
Women were just as vulnerable as men to receiving blows to the head, suggesting that many of the attacks occurred during raids on neighboring villages or as revenge attacks.
"The first victim you find, you kill to satisfy the group's urge for revenge," Schulting said.
Few of the skulls in the sample belonged to children, but Schulting and Wysocki don't think that this means that kids were spared from the brutality.
"One of the adolescents in our sample had a horrific injury, with half of his head caved in," Schulting said.
All of this violence would have made for a jittery society, Schulting says.
"It would have put fear into people, affecting how they perceive their neighbors."
What's more, he says, the finding sheds a different light on the extensive trading that occurred at the time, making travel appear a more dangerous activity than previously thought.
But not everyone is convinced that Neolithic Britain was such a barbarous place.
Tim Sutherland is an expert on conflict archaeology from the University of Bradford in West Yorkshire.
He said, "The sample size is too small and may not be representative of the population in general.
"It is possible that only special people were buried in these long barrows."
Schulting agrees that his survey is only a start, but he believes that the mortuaries give a reasonable cross-section of Stone Age society.
"Because they contain men, women, and children, we think that this is more or less what people were like," he said.
Free Email News Updates
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).
SOURCES AND RELATED WEB SITES