Why multilingual, and how to keep it-An evolutionary dynamics perspective.

Zhijun Wu

doi:10.1371/journal.pone.0241980

Abstract

While many languages are in danger of extinction worldwide, multilingualism is being adopted for communication among different language groups, and is playing a unique role in preserving language and cultural diversities. How multilingualism is developed and maintained therefore becomes an important interdisciplinary research subject for understanding complex social changes of modern-day societies. In this paper, a mixed population of multilingual speakers and bilingual speakers in particular is considered, with multilingual defined broadly as zero, limited, or full uses of multiple languages or dialects, and an evolutionary dynamic model for its development and evolution is proposed. The model consists of two different parts, formulated as two different evolutionary games, respectively. The first part accounts for the selection of languages based on the competition for population and social or economic preferences. The second part relates to circumstances when the selection of languages is altered, for better or worse, by forces other than competition such as public policies, education, or family influences. By combining competition with intervention, the paper shows how multilingualism may evolve under these two different sources of influences. It shows in particular that by choosing appropriate interventional strategies, the stable co-existence of languages, especially in multilingual forms, is possible, and extinction can be prevented. This is in contrast with major predictions from previous studies that the co-existence of languages is unstable in general, and one language will eventually dominate while all others will become extinct.

Highlights

As the world becomes increasingly globalized, more people become multilingual across the continents
While many languages are in danger of extinction, multilingualism is being adopted as a common way of communication among different language groups, and is playing a unique role in preserving language and cultural diversities [2]
By combining language competition with possible societal interventions, this paper shows how multilingualism may evolve under these two different sources of influences

Summary

Introduction

As the world becomes increasingly globalized, more people become multilingual across the continents. It is a system of replicator equations with payoff functions P~A and P~B, and corresponds to an evolutionary game, with the Nash equilibrium being a strategy ðxA ; xB Þ such that p~ððxA ; xB Þ; ðxA ; xB ÞÞ p~ððxA; xBÞ; ðxA ; xB ÞÞ Consider the dynamic behaviors of a bilingual population under the influences of both inter-language competition and external interventions, as modeled by the system in (10) and the corresponding game in (14).

Results

Conclusion