Mixed effect models for genetic and areal dependencies in linguistic typology

Abstract

1. Introduction 1.1. Summary of Atkinson 2011 Atkinson (2011) sets out to test the so-called “serial founder model” against crosslinguistic data on phonological diversity. In his words (Atkinson 2011: Supporting Online Material: 3), the serial founder model predicts that [. . . ] during population expansion, small founder groups are expected to carry less phonemic diversity than their larger parent populations. A series of founder events should produce a gradient of decreasing phonemic diversity with increasing distance from the origin. To test this hypothesis, Atkinson employs a sample of 504 non-extinct languages from WALS (Haspelmath et al. (eds.) 2008), for which the number of vowels, the number of consonants, and the number of tones in the language are annotated (Maddieson 2008a, b, c). For the main analysis, these three measures were standardized (i.e., the mean was subtracted from each value, which was then divided by the standard deviation of the measure) and averaged into one combined measure of the total phonological diversity of a language. This normalized phonological diversity measure ranges from −1.19 to 1.68 (mean =0.02). Each language is also annotated for its coordinates on the globe as well as it population size (the number of speakers).