Importance of interlinguistic similarity and stable bilingualism when two languages compete

TL;DR

This paper models language competition dynamics, showing that stable bilingualism and language coexistence depend on linguistic similarity and equal status, challenging previous assumptions about language extinction.

Contribution

It introduces a mathematical model linking language similarity and status to long-term coexistence and stable bilingualism, providing new insights into language competition outcomes.

Findings

Stable bilingualism requires sufficient language similarity.

Long-term coexistence is possible with stable bilingual groups.

Similarity and status symmetry promote language coexistence.

Abstract

In order to analyze the dynamics of two languages in competition, one approach is to fit historical data on their numbers of speakers with a mathematical model in which the parameters are interpreted as the similarity between those languages and their relative status. Within this approach, we show here, on the basis of a detailed analysis and extensive calculations, the outcomes that can emerge for given values of these parameters. Contrary to previous results, it is possible that in the long term both languages coexist and survive. This happens only when there is a stable bilingual group, and this is possible only if the competing languages are sufficiently similar, in which case its occurrence is favoured by both similarity and status symmetry.