Why was matrilineal inheritance common in many Micronesian islands?

In traditional Micronesian societies, descent was traced through matrilineage in most areas, though the specific reasons for this structure were often tied to the practical management of resources and labor.1

While matrilineal descent was the standard, the organization of family groups remained flexible to accommodate environmental and economic needs. The primary determinants for where a newlywed couple resided—and consequently how they accessed resources—were the availability of agricultural land and the requirement for additional laborers on either the husband's or the wife's side of the family.1

Although residence with the wife’s family was widely considered the ideal, practice often allowed for exceptions. For instance, children frequently maintained rights to use land on their paternal grandmother’s side, demonstrating a pragmatic approach to land access. This flexibility extended to lineage membership itself; if a lineage became too large, it would split, and outsiders could be incorporated as honorary members to ensure the community functioned effectively.1

In contrast to this widespread pattern, some islands, such as Yap, favored patrilocal residence and patrilineal inheritance of land as their ideal system.1