As the early peoples adapted to their new environments, a series of interesting cultural developments occurred. In the initial period following arrival, groups did not need to venture far since the areas were rich in resources. But over time as population growth caused resources to come under strain, groups dispersed and formed new collectives. Too often South Polynesia, and indeed wider Polynesia, has been characterized as homogenous when it is anything but. The material cultures and economies of Polynesia were determined by the land and the resources available. Essentially, the process of adaptation of South Polynesian groups to their environments modified the cultures from East Polynesia to recognizable cultures influenced by their new locations. For example, Māori society, while heavily influenced by Polynesian origins, became distinguishable around the turn of the sixteenth century. This section explores developments in sociopolitical organization, settlements and fortifications, and art that reflect this distinctiveness.

In order to understand the structure of Māori—and to a certain extent Moriori and Rapanui—societies some key concepts need to be outlined: whakapapa, mana, and tapu. Whakapapa is often translated as “genealogy” and while this is certainly part of it, it does not capture the complexity of the term. Whakapapa pervades every aspect of the Māori world and is the foundation of Māori knowledge. Everything in the world has whakapapa, and at the heart of the concept are relationships and connections, whether these be kin-based or not. It is how everything is connected. Mana is spiritual force or power, while tapu is generally translated as sacred, although once again the complexities are hard to translate. Mana and tapu played a role in all three societies, with whakapapa also being central to Māori and Moriori social political organization. Between 1200 and 1500 CE these concepts were developing and becoming more defined.

It has now generally been accepted that there has always been some form of leadership in Māori society. These leaders derived their authority from both their ancestry and their personal attributes. In terms of inheriting leadership, there was a preference for firstborn males. This has been shown through oral traditions, many of which centre on the tales of chiefs or key ancestors after whom social groupings were named. A common theme is that the chiefs were born of a high-ranking line but they achieved their leadership status through their own merits and abilities.