The life cycle of phonological patterns explains drift in sound change

This paper addresses a classic problem in historical linguistics — ‘drift’, i.e., identical or similar changes occurring in related languages after separation from their common ancestor — from the perspective of theoretical historical phonology. I endorse Joseph’s (2006) view of the basic mechanism of drift: it arises when synchronic variation, inherited from the proto-language, narrows in range to produce similar outcomes. This paper elaborates on this proposal by identifying the mechanism that ensures inherited variation is narrowed down in similar ways, framing it within the theory of the life cycle of phonological processes.

As proposed by Sapir (1921), ‘drift’ is often criticized for invoking the spectre of unexplained teleological factors (‘submerged form-feeling’) driving change. It is reasonable to ask whether parallel developments involved in ‘drift’ are ever distinct from ‘ordinary’ change. After all, change is subject not only to random contingencies but also to universal forces, which can conspire to produce parallel developments. This is especially pertinent for phonological change, widely agreed to be grounded in substantive biases related to the human articulatory and auditory systems (Blevins 2004).

If we wish to disentangle the mechanism that might account specifically for drift from such universal tendencies, it is particularly valuable to consider cases of drift with no ready universal explanation — those that involve typologically unusual phenomena. Here, I discuss the consonant gradation systems of the Uralic languages, with a particular focus on the Finnic and Sámi branches. I offer a reconstruction of its rise and development within the life-cycle framework. In doing so, I highlight both the explanatory power of the theory in accounting for Sapirean drift and its heuristic value in opening up new approaches to long-standing empirical controversies.