The GINI project investigates the dynamics of inequality among populations over the long term by synthesising global archaeological housing data. This project brings archaeologists together from around the world to assess hypotheses concerning the causes and consequences of inequality that are of relevance to contemporary societies globally.

Domestic architecture is increasingly revisited as a source of data about wealth inequality in the distant past via the Gini coefficient, a statistical tool often used in economics to compare income inequality. Many areas—including South America, Africa, South Asia and Oceania—remain under-sampled, making it difficult to develop a more complete picture of ancient political economies. In this paper we present a first look at this measure in the Hawaiian Islands. These data show that during the period prior to contact with Europeans inequality was extremely high, most similar to autocratic archaic states. We also found geographic patterning that may ultimately be linked to dryland (non-irrigated) farming. On islands reliant on dryland farming (Mau‘i, Hawai‘i), we find distinctively less inequality than elsewhere, or larger house sizes. We hypothesize these may have been innovations in how wealth was made visible to create and maintain cooperation in places where more labour would have been required to grow surplus. More research is necessary to test this hypothesis, investigate alternative interpretations, and to put these findings in larger regional context within Polynesia.

Identifying and explaining the end of long-lived practices is a major challenge for anthropological archaeology. We present a high-precision uranium series dating (230Th/U) chronology of an undocumented aspect of Hawaiian religion: the use of corals as offerings in gardens. Our results from the upland gardens of Kealakekua (Kona District, Hawai`i Island) document the onset of religious offerings at the same time as farming in the area at around AD 1400, with no samples dating to after around AD 1635. There are similar conspicuous endings to coral offerings in temple sites on the small, isolated island of Nihoa and in the uplands of Maui. On Nihoa, the lack of coral offerings after AD 1606 can be reasonably linked to the abandonment of permanent settlement on the island. In upland Maui temple sites, as is the case in the upland gardens of Kealakekua, the end of coral offerings around AD 1600–1700 suggests a disruption to a long-lived ritual tradition at a time when other metrics point to the rise of state authority over religion.

As lidar becomes a regular part of surveying, ground-based platforms (handheld, mobile, and terrestrial lidar) and airborne platforms (piloted aircraft) are being joined by unpiloted aerial vehicle (UAV)–acquired lidar. We present a method for leveraging UAV-acquired lidar data with data collected using different lidar platforms (terrestrial and piloted aircraft), at a range of resolutions (1 to +1,000 points per m2) and geographic scales. We use these instruments to document a dry-masonry stone wall enclosing a religious precinct within the royal center at Kealakekua, Kona District, Hawai'i Island. Prior to European contact in AD 1779, Kealakekua was the center of the island-wide polity during the annual Makahiki festival. Results of this study suggest that when the wall was constructed around AD 1640, it was the largest structure ever built on the island of Hawai'i as well as a strong material expression of the power of state religion and the Makahiki rituals.

Reconstructing routes of ancient long-distance voyaging, long a topic of speculation, has become possible thanks to advances in the geochemical sourcing of archaeological artifacts. Of particular interest are islands classified as Polynesian Outliers, where people speak Polynesian languages and have distinctly Polynesian cultural traits, but are located within the Melanesian or Micronesian cultural areas. While the classification of these groups as Polynesian is not in dispute, the material evidence for the movement between Polynesia and the Polynesian Outliers is exceedingly rare, unconfirmed, and in most cases, nonexistent. We report on the first comprehensive sourcing (using a portable X-ray fluorescence spectrometer) of obsidian and volcanic glass artifacts recovered from excavations on the Polynesian Outlier island of Tikopia. We find evidence for: (1) initial settlement followed by continued voyages between Tikopia and an island Melanesian homeland; (2) long-distance voyaging becoming much less frequent and continuing to decline; and (3) later voyaging from Polynesia marked by imports of volcanic glass from Tonga beginning at 765 cal yr BP (±54 yr). Later long-distance voyages from Polynesia were surprisingly rare, given the strong cultural and linguistic influences of Polynesia, and we suggest, may indicate that Tikopia was targeted by Tongans for political expansion.

Powerful hurricanes in 2017—Hurricanes Harvey, Irma, and Maria—were stark examples of how these previously rare catastrophes are becoming increasingly normal due to climate change, with dire consequences for cultural resources. These storms, sometimes called megastorms or superstorms, were the first in which high-resolution satellite imagery was available in the immediate aftermath, providing a new tool for rapidly evaluating damage to archaeological sites. Using Hurricane Harvey as a case study, we examined two recent spatial models of archaeological site vulnerability to long-term climate change to determine whether these models are also adequate for predicting the impacts of short-term climate catastrophes. We further examined a number of individual variables that we expected to be useful in predicting which sites would be most vulnerable to flooding, such as proximity to rivers, the coast, or the floodplain. Neither the models nor the individual variables correlated well to increased risk to archaeological sites, with the exception of land use. Sites located within developed areas benefited from measures to protect property and were less often flooded. We suggest that strategies for responding to megastorms would be most effective through a combination of preparedness, analysis of remote sensing data, and existing field research methods.

Archaeologists commonly use the onset of the construction of large burial monuments as a material indicator of a fundamental shift in authority in prehistoric human societies during the Holocene. High-quality direct evidence of this transition is rare. We report new interdisciplinary research at the archaeological site of Nan Madol that allows us to specify where and when people began to construct monumental architecture in the remote islands of the Pacific. Nan Madol is an ancient administrative and mortuary center and the former capital of the island of Pohnpei. It was constructed over 83 ha of lagoon with artificial islets and other architecture built using columnar basalt and coral. We employed geochemical sourcing of basalt used as architectural stone and high-precision uranium-thorium series dates (230Th/U) on coral from the tomb of the first chief of the entire island to identify the beginning of monument building at Nan Madol in AD 1180-1200. Over the next several centuries (AD 1300-1600) monument building began on other islands across Oceania. Future research should be aimed at resolving the causes of these social transformations through higher quality data on monument building.

Through intensive archaeological investigation of temples in Hawai'i, the authors reveal a sequence of religious strategies for creating and maintaining authority that has application to prehistoric sequences everywhere. Expressed in the orientation and layout of the temples and their place in the landscape, these strategies develop in four stages over the course of a few hundred years, from the fifteenth to nineteenth century AD, from local shrines associated with agriculture to the development of a centralising priesthood serving the larger political economy.

Building directly upon a previous summary of 45 dates (Weisler 1989), this paper presents radiocarbon age determinations for 175 samples from archaeological and natural contexts and a revised culture history of Moloka'i Island, Hawai'i (cal AD 800 and 1795). Significant culture historical trends include an early settlement pattern apparently generalized with respect to ecozone; a remarkably long initial period of marine and endemic bird exploitation; strong material evidence for the concurrent intensification of subsistence economies, population increase, and the structuring of the social landscape through ritual; and links between island politics as described in oral traditions and site construction. Moreover, these results support a late chronology for the colonization of Hawai'i and demonstrate the value of spatial technology for building large chronometric databases.