Traditional explanations of Rapa Nui history invoke environmental degradation and warfare to explain the ‘collapse’ of the island's social and economic structure. One element in these reconstructions are the stemmed obsidian points known as mata'a, which some have envisaged as spearheads produced in the context of endemic warfare. Morphometric analysis shows, however, that mata'a were not specifically designed for interpersonal violence but were general purpose tools that may have been used for peaceful tasks such as ritual scarification. This discovery provides further evidence against the theory of the violent collapse of Rapa Nui society.