How crow-omaha skewing spreads

Crow-Omaha kinship systems skew kin terms intergenerationally. Although occurring worldwide, they are relatively infrequent and often exist in historically unrelated clusters: “similar inventions in areas widely apart” (per Boas). Most analyses have been formalist, evolutionist, or sociological. Here, adding some historical linguistics and focusing on the core kin-term equations via the ethnographic and ethnohistoric record of Indigenous Australia and North America, we examine how these systems arise and spread among near neighbors, and across language-family boundaries. We address comparative dynamics, sociological and linguistic, of distribution patterns over time and space. We suggest that skewing, as a social technology that enhances matrilineal-matrilocal (Crow) and patrilineal-patrilocal (Omaha) systems (with some similar and other converse patterns), confers advantages over systems with “crossness” of “Iroquois” or “Dravidian” type in circumstances of demographic stress. We affirm the key to skewing lies in its dispersal of affinal alliance beyond binary exchange and suggest some socio-evolutionary implications.