Using Historical Glottometry to Subgroup the Early Germanic Languages

Historical Glottometry, introduced by Kalyan & François (2018), is a wave-based quantitative approach to language subgrouping used to calculate the overall strength of a linguistic subgroup using metrics that capture the contributions of linguistic innovations of various scopes to language diversification, in consideration of the reality of their distributions. This approach primarily achieves this by acknowledging the contribution of postsplit areal diffusion to language diversification, which has traditionally been overlooked in cladistic (tree-based) models. In this paper, the development of the Germanic language family, from the breakup of Proto-Germanic to the latest period of the early attested daughter languages (namely, Old English, Old Frisian, Gothic, Old High German, Old Low Franconian, Old Norse, and Old Saxon) is accounted for using Historical Glottometry. It is shown that this approach succeeds in accounting for several smaller, nontraditional subgroups of Germanic by accommodating the linguistic evidence unproblematically where a cladistic approach would fail.