War May Not Have Led To Easter Island's Ancient Collapse

What caused the collapse of Easter Island, widely believed to be the world's most isolated inhabited place, hundreds of years ago? The question is a matter of hot debate.

Conventional wisdom holds that environmental destruction and internecine warfare led to societal and economic collapse on this tiny island located some 2,150 miles off the coast of Chile. For years, the island's demise has been presented as a cautionary tale for our own violent and environmentally destructive times.

But in the past decade or so, the common understanding of Easter Island's collapse has been challenged by archaeologists whose fieldwork and research on the island, also known as Rapa Nui, point to a different story — in which disease and slavery, introduced by Europeans, are more to blame than ecocide and self-destruction.

A study published Tuesday in the journal Antiquity adds further evidence to this line of thinking.

Scattered across the island are thousands of small, sharp objects carved from obsidian, a rock made of volcanic glass. For centuries, it's been assumed that these implements, roughly triangular and known in the indigenous Rapanui language as mata'a, were spear points — they were referred to as spears by European explorers, who began reaching the island in 1722.

But after analyzing 423 mata'a, a team of scientists has concluded that they "were not specifically designed for interpersonal violence but were general purpose tools that may have been used for peaceful tasks" such as agriculture, ritual scarification, even tattooing.

"They found that the pieces of glass would have made very poor weapons and bore little resemblance to other types of spears from similar civilizations," says The Washington Post.

"It's assumed that these are the WMDs that led to the collapse of people," the study's lead author, Carl Lipo, an anthropologist and director of Binghamton University's environmental studies program, told the BBC. "And what we found was there was no evidence, in fact, to support that these were used in a systematic, lethal fashion, and that they're best explained as cultivation tools and things used in daily household activities."

How do they know?

Usually, Lipo tells NPR via email, "when we see lethal weapons used in combat, they are long, narrow, symmetric, pointed — best suited for piercing one's internal organs. Those kinds of shapes are best performing when you are in hand-to-hand combat and you need to dispatch your enemy as quickly as possible (lest they kill you)."

But in the case of the Easter Island mata'a, Lipo notes, "We find anything but long, thin, narrow, pointed — we find any range of shapes, lack of symmetry, non-pointedness, thick objects that had sharp edges (as volcanic glass) but were nearly useless in the 'lethal spear' sense. When we compare the mata'a shapes with other Polynesian weapons that seemed to be used as actual spears ... they are completely different. What they most closely resemble are objects that are used in a general fashion as scrapers [or] cutting implements."

Still, even if the mata'a "weren't arrow-shaped or perfect stabbing weapons ... that might not matter," says the Christian Science Monitor. "Attached to the end of a stick, the glassy objects could do some gruesome damage as a slashing weapon."

Lipo points out there is no evidence of defensive structures on the island. "On other islands where we see lethal, inter-group warfare, we see clear evidence of hilltop fortresses," he writes. "The hilltops are the best place to defend whenever weapons are thrown."

But on Easter Island, "none of the tops of the hills have any evidence of such features," he says. "Nothing."

In fact, Lipo and his co-authors note in their study:

"Rock throwing from high points was the primary way in which native Rapanui fought Europeans and would have more probably been used as a mode of lethal force than mata'a. This conclusion does not imply that prehistoric islanders did not experience violence, only that mata'a do not appear to be related to systemic warfare where performance as lethal weapons would be paramount."