Lexical replacement and cognate equilibrium in Australia

Abstract

We estimate the degree to which languages resort to borrowing as a means of lexical replacement, within a group of neighbouring languages of southwestern Cape York Peninsula, using several methods: (1) sound‐correspondences and correspondence‐mimicry; (2) the proportion of ‘local’ words in single‐language lists; and (3) the creation of the vocabulary of special registers. We find that borrowing accounts for at most half of lexical replacement in these languages, and most usually is well below half. We demonstrate that this rate is crucial in the prediction of what fraction of vocabulary might in the long term be common to two neighbouring languages (the ‘equilibrium percentage') in a model of lexical similarity that does not distinguish borrowings from common retentions. We then apply these findings to the case study, and compare determinations by lexicostatistical subgrouping (with and without recognition of loans), with results from classification by classical means. We find substantial agreement, and that the effect of ‘borrowing to equilibrium’ on lexicostatistical subgrouping is tolerably small.