Core argument patterns and deep genetic relations
It has been proposed that patterns of core argument marking have high genetic stability and strong resistance to areal influence, making them good indicators of deep genetic relationships (Nichols 1992). Patterns in four languages of Northern California indicate that this is not necessarily the case. Chimariko, Yana, Yurok, and Karuk all show hierarchical systems, cited as the rarest pattern crosslinguistically (3%). The languages are geographical neighbors but not genetically related. The systems share no substance and vary considerably in detail. Chimariko shows a basic agent/patient organization, Yana and Yurok nominative/accusative, and Karuk a mixture. The hierarchies differ. The extent to which the system has penetrated their grammars varies. The constructions exploited to maintain the hierarchies differ. The development of the systems was apparently stimulated by contact, as bilinguals carried discourse behaviors from language to language, stylistic propensities which ultimately crystallized into grammar.