Thousands of small, sharp, spearlike objects scattered throughout Easter Island have long been presumed to be evidence of massive warfare that led to the demise of its ancient civilization. But new evidence from archaeological investigations suggests that these objects, called mata'a, were not used as weapons at all.

Easter Island is a tiny landmass located about 2,300 miles (3,700 kilometers) off the coast of Chile. The remote volcanic island, also known as Rapa Nui, has been at the center of fierce debates in both academia and popular culture.

Polynesians first arrived on the island in the 13th century, and Rapa Nui's early inhabitants were famous for the enormous stone statues (called moai) that they built and placed on the coastline. More than 900 of these majestic statues were found on the island — so many that scholars have argued that there must have been tens of thousands of residents on Easter Island at one point — but so far, scientists and historians have not been able to agree on what caused the collapse of its society. [Image Gallery: The Walking Statues of Easter Island]

Popular belief held that massive internal warfare led to the population's catastrophic collapse. This grim outcome became a cautionary tale of the overuse of limited resources and eventual self-destruction. But, in the past decade or so, this understanding has been challenged by archaeologists whose research points to a different story — in which disease and slavery introduced by Europeans were the more likely cause of the Polynesian society's decline.

By carefully examining more than 400 mata'a, collecting photographs and analyzing their shape using a technique known as morphometric analysis, researchers have added new evidence to this line of thinking.

"The mata'a have lots of different shapes," said lead study author Carl Lipo, an anthropologist at Binghamton University in New York. "Some of them are roundish, some of them are square and some are kind of triangular."

The mata'a would not have made good weapons, Lipo said. For one, they are not sharp, and not all of the mata'a are pointed. They are also too thick and asymmetrical for piercing lethal wounds, and the wear patterns on these objects suggest that they were used to scrape and cut things, rather than puncture vital organs, he said.

These are images of various mata'a. (Image credit: Carl Lipo, Binghamton University)

Moreover, other evidence of systemic warfare on the island is mysteriously absent, according to the researchers. For instance, archaeological digs on Easter Island have not uncovered traces of lethal skull trauma, severed limbs or mass graves, Lipo said. Nor did scientists find defensive fortlike structures common on other islands in the Pacific with a history of warfare, such as Fiji and New Zealand.

"There's no question that there's going to be competition on the island," Lipo told Live Science. "It is an island with finite resources. But the interesting thing is that it doesn't appear to have led to lethal violence."

All of this evidence suggests that the small population of 3,000 that was living on the island when Europeans first arrived in 1722 wasn't a relic of a much greater civilization. In fact, the Rapa Nui society probably flourished until well after initial European contact, according to Mara Mulrooney, an anthropologist at the Bishop Museum in Honolulu, who also studies the Rapa Nui civilization but was not involved with the new research.

The researchers' "morphometric analysis of mata'a lends further empirical support to the notion that Rapa Nui is an example of success rather than 'collapse,'" Mulrooney told Live Science in an email.

The Rapa Nui mata'a were probably general-purpose tools used for agricultural practices such as lithic mulching, ritual sacrifice and tattooing, Lipo said. These peaceful activities actually make more sense in an archaeological context because on such a small, isolated island, people would have had to learn to deal with their problems and mitigate group-level competition, he added.

"You can't afford to escalate to killing because there's no way to escape the cost of killing," Lipo said. "Warfare would have killed everybody."

If the Rapa Nui civilization was successful on the remote island, the next question archaeologists need to answer is how these people created a sustainable community, Lipo said. "The mystery is actually more interesting now," he said, "because now, we have something to learn."

The new study was published online Feb. 17 in the journal Antiquity.

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