Indo-Aryan – a house divided? Evidence for the east–west Indo-Aryan divide and its significance for the study of northern South Asia

In this study, we investigate the possible presence of an east–west divide in Indo-Aryan languages suggested in previous literature (Peterson, John. 2017a. Fitting the pieces together – towards a linguistic prehistory of eastern-central South Asia (and beyond). Journal of South Asian Languages and Linguistics 4(2). 211–257.), with the further hypothesis that this divide may be linked to the influence of the Munda languages, spoken in the eastern part of the subcontinent. Working with 217 fine-grained variables on a sample of 27 Indo-Aryan and Munda languages, we test the presence of a geographical divide within Indo-Aryan using computational methods such as cluster analysis in combination with visual statistical inference. Our results confirm the presence of a geographical divide for the whole dataset and most of the individual features. We then proceed to compute the degree of similarity between the Indo-Aryan languages and Munda, using a Bayesian alternative to a t-test. The results for most features support the claim that the languages identified in the eastern clusters are indeed more similar to Munda, thereby opening up further research scenarios for the history of this region