Lineages function as territorial units, inhabiting a common settlement and normally foster mutual cooperation and support among their members, often focusing on organizing alliances and battles in a cycle of endemic warfare. Their central dynamics are set in motion by their role in the marriage exchange system. They are exogamous and their members consult jointly in the selection of marriage partners for their sons and daughters within the web of marriage exhanges with allied lineage groups.
The marriage system normally acts to construct regular relationship between pairs of lineages who regularly intermarry through a system of bilateral cross cousin marriage. Intermarrying units tend to pair off and exclusively occupy the same village, thereby generating a moiety system. Members from other lineages may also reside in the village and marry within it, but two intermarrying moieties will usually dominate the settlement both numerically and socially. When lineages segment they usually include their closest affines when migrating to a new settlement, thereby reproducing the moiety structure.
Paired Intermarrying Lineages
Note: lines connecting people from below indicate marriages.
Yanomamo lineages may be said to exert a limited range of corporate functions through collective rights to marry off their women and claim wives in exchange within the marriage system. Beyond this, the group does not manage joint assets, such as land, that frequently assume importance in other unilineal societies.