Why is the date of eastern Polynesian settlement harder to determine than that of western Polynesia?

Determining the date of settlement for eastern Polynesia is more challenging than for western Polynesia primarily due to the absence of Lapita culture ceramics in eastern archaeological sites.1

While western Polynesia was settled by people associated with the Lapita culture—who are well-known for their distinctive pottery—these ceramics are entirely absent from the archaeological record in eastern Polynesia. This lack of pottery removes a key diagnostic tool that archaeologists typically use to establish chronologies and identify cultural transitions in the region.1

Although it is possible that some eastern islands were occupied shortly after the arrival of Lapita colonists in the west, the "puzzling thousand-year gap" in the archaeological record between the settlement of western Polynesia and the later occupation of central and eastern island groups remains a subject of ongoing study. Researchers must rely on other, often less definitive, evidence to reconstruct these timelines, as the material culture in the east lacks the clear, datable ceramic markers found in earlier western sites.21