Supplementary materials for "Dialect differences and linguistic divergence: A cross-linguistic survey of grammatical variation" by John Mansfield, Henry Leslie-O’Neill and Haoyi Li, published in LDC, 2023
These are the supplementary materials for an article published in Language Dynamics and Change, entitled "Dialect differences and linguistic divergence: A crosslinguistic survey of grammatical variation", by John Mansfield, Henry Leslie-O'Neill and Haoyi Li with DOI: 10.1163/22105832-bja10026. This article presents a new type of comparative linguistic survey, analyzing (socio)linguistic variation in a database of 1,155 grammatical constructions drawn from 42 diverse languages. We focus in particular on variation in the expression of grammatical meanings, and the extent to which grammatical variation differentiates geographic dialects. This is the first study we know of to present a systematic, crosslinguistic survey of dialect differentiation. We identify three main structural types of grammatical variation— form, order, and omission—and find that in situations of close contact between dialects, where signaling of distinct group identities is more relevant, form variables are more likely to differentiate dialects than the other two types. Order and omission variables usually only differentiate dialects that have minimal contact. Our survey suggests that social signaling may have a substantial role in the divergence of grammars, and provides systematic support for previous proposals regarding convergence and divergence under contact.
In the supplementary materials, we include further information on the selection of reference grammars and their bibliographic details. We also describe the process for identifying grammatical variables and how they were categorised into structural types, and provide more information about the coding of social distance, and our tests for inter-coder reliability. Finally, we present an alternative regression model without random slopes for language family by structural type, which provides very similar results to the model presented in the main paper.