Social practice and physical environment shape Pama-Nyungan kinship macroevolution, but not into stable typologies

Abstract

**Author(s):** Sheard, C; Bowern, C; Jordan, F M Introduction: Human kinship systems, or how different cultural groups use language to classify family members, show remarkable global diversity, but they also seem to be constrained by social and cognitive limits. It is common within anthropology, for example, for kinship systems to be categorised into a mere six typologies, based on a few axes of variation in cousin terms. Despite the importance of kinship in structuring human society, however, there has been little work examining the cross-cultural drivers of, and constraints on, this diversity, and most of this scholarship has been limited to a handful of well-documented language families. Materials and Methods: Here, we present a survey of kinship systems in 71 Pama-Nyungan languages, representing all major branches of the largest Australian language family. We first describe the macroevolutionary dynamics of Pama-Nyungan kinship and test for evidence of stable kinship typologies. We then test hypotheses related to how social practice and spatial variables shape kinship systems. Results: We find only weak support for any clustering of languages by kinship system or for specific holes within the observed volume of kinship space, instead demonstrating that these ethnolinguistic groups’ kinship systems have evolved steadily over the past ~ 6,000 years. We find that community marriage norms, but not post-marital residency, correlate with kinship system. Furthermore, though we find evidence of spatial autocorrelation in the data above and beyond the effect of shared phylogenetic history, we find that spatial similarity in kinship systems is better explained by a correlation between kinship and the physical environment. Conclusions: By applying modern phylogenetic comparative methods to the study of language-culture coevolution, we thus demonstrate the importance of moving beyond traditional typological comparisons in the study of kinship, as well as caution against assuming the universal applicability of cultural evolution trends across all geographic and linguistic contexts.