Ancient structures discovered in Samoa offer clues to origins of inequality

A new study by archaeologists at the University of Auckland may have revealed the origins of hierarchical society in Samoa and across Polynesia.

New research reveals that the recent discovery of ancient rock walls, towering mounds and deep ditches in the thick jungles of the Falefa Valley on the island of Upolu in Samoa offers important insights into the roots of land ownership and social stratification in Polynesian culture.

Led by Waipapa Associate Professor Ethan Cochrane Taumata Rau of the University of Auckland, the study draws new links between a dramatic increase in Samoa’s population, richer agricultural land in some areas and the beginnings of land demarcation and associated social status.

These connections have generated a lot of interest among ordinary Samoans, Cochrane says.

“They have the most intimate knowledge possible of their territory and are now able to compare the ancient political and village boundaries revealed by archaeology with modern boundaries and those known by oral tradition, and to see where the differences lie.”

The team’s fieldwork in Samoa revolved around LiDAR (Light Detection and Ranging), a mapping technology that uses light in the form of a pulsed laser to measure varying distances from the Earth, from which it creates a topographic map.

The crucial element, Cochrane explains, is that when you fly it from an airplane, LiDAR penetrates small openings in thick foliage to reveal what would otherwise be covered by a forest canopy.

“This technology has been used for 15 to 20 years in the Pacific and it can destroy even a dense jungle environment. This is one of the first times it has been used in Samoa, which allows us to look in detail at all these impressive rock walls, platforms and mounds, which are 600 to 900 years old.”

Field challenges and architectural discoveries

Slogging through dense bushes in pouring rain and blazing sun, attacked by mosquitoes at every turn, in “Indiana Jones-style archaeology,” Cochrane says, may not be for everyone, but the rewards, in this case, are worth any discomfort.

“These structures, seen up close, are incredible pieces of architecture. Some were family dwellings made of stone and earth, as seen in some Samoan villages today; others were civic building projects or ceremonial projects. Some are what are called ‘star mounds’, which are up to two metres high and were probably used to trap pigeons, which was mainly a sport.”

The study, which was conducted in partnership with the National University of Samoa and with permission from local villages, is not the first to discover these structures, but it is the first to link when and why they were built to what it calls a “collective action problem,” he says.

“We found that this construction – miles-long stone walls that limit access to the land, ditches for irrigation to create a productive wetland agricultural system – is a response to a massive population increase in Samoa that we know happened at that time (900 years ago).”

“In this case, sharing resources with everyone would mean less for everyone, so the question becomes: ‘At what point does it become advantageous for individuals to contribute to collective defense at the expense of themselves and to exclude other groups from access to group resources?'”

After this rapid increase in population in the valley, he said, people did just that; they fenced off areas to separate them from others in order to preserve their own access to a valuable resource.

“In this case, the oldest massive rock walls are located near more fertile lands in the western and northern parts of the valley, something we know from analyzing soil samples in the area of ​​these structures.”

It’s possible that the entire Samoan chieftaincy system, which is found throughout Polynesian society in general, was based on who had access to land in those early days, and who didn’t, Cochrane says, and that this may have also been the reason for similar changes in early societies around the world.

“We have often wondered why hierarchical societies have emerged across the planet over the millennia, when about 20,000 years ago most human societies were more equitable and there were fewer positions of status and power among hunter-gatherers.

“Today we live at the other extreme, where many societies, if not all, have statuses, hierarchies and levels where some people have unimaginable power and others have nothing.”

Reference: “Collective Action Problems Led to Samoa’s Cultural Transformation 800 Years Ago” by Ethan E. Cochrane, Seth Quintus, Matthew Prebble, Ta’iao Aumua Ausilafa’i Matiu Tautunu, Dolly Autufuga, Mana Laumea, Alexandra Queenin, Paul Augustinus, and Noa Kekuewa Lincoln, June 20, 2024, PLOS ONE.
DOI: 10.1371/journal.pone.0304850