Correlates in the evolution of phonotactic diversity in English: Linguistic structure, demographics, and network characteristics

Abstract

There is an ongoing debate as to whether linguistic structure is influenced by demographic factors. Relationships between these two domains have been investigated on the phonological, morphological and lexical level, mainly drawing on synchronic data and comparative methodology. In this exploratory study, by contrast, we focus on the lesser recognized level of phonotactics, and adopt a methodologically orthogonal approach. We investigate the diachronic development of a single lineage, namely English, and compare it with concomitant developments of the demography of the English-speaking population. In addition to linguistic and demographic factors, we also derive characteristics of the underlying speaker network (network diameter; clustering coefficient). Empirically, we focus on the system of English consonant clusters, which we argue to be particularly sensitive to linguistic change so that effects of demography are expected to be more clearly visible than in more robust linguistic subsystems (e.g. phoneme inventory; morphology). By employing time-series clustering, it is shown that the trajectory of phonotactic diversity in English coda clusters most closely matches that of covariates related with density and heterogeneity of the speaker population. Linguistic covariates are less closely related. We conclude that heterogeneity of the linguistic input and the number of informants a learner is exposed to are relevant factors in the evolution of phonotactic diversity.