Investigating contact languages with agent-based modelling

Abstract

The spread, development, diversification, and extinction of the world’s languages have been some of the central topics in the field of language evolution and sociolinguistics. Rooted in relatively recent cases of language emergence and language contact, in which the sociohistorical and multilingual contexts are highly complex, the current thesis employs agent-based models and computational network structures to evaluate the role of non-trivial social structures in language propagation, language death and lexical development. The study aligns social factors and the developmental trajectory of creole languages as observed empirically. An artificial communication game, which is inspired by the Naming Game, has been employed to simulate the interaction between agents. Based on previous research, complex network structures with various topological features have been incorporated into the simulation, which aims at predicting the spread and change of languages in a heteroglossic and multilingual ecology. The model has expanded the previous models by considering the quantification of different social structures, i.e., the status of internal stratification within a social group based on different socioeconomic status, and the frequency of inter-group communication across different social groups/ethnics. The model supplements the previous studies by offering a plausible explanation as of why previous model may have predicted a high chance for creole emergence when there was none historically. Based on the previous model, the game has been modified to cater the emergence and spread of lexical items. A model has been constructed to investigate the relexification process, in which the agents select and discard competing linguistic forms for a particular semantic meaning. The model explores how the development of lexicon can be affected by the population dynamics, with a particular reference of the situation of Suriname, in which a large proportion of English native speakers exited the colony at an early stage of the creole development. Furthermore, the mechanism for the genesis of variation continuum, as partially conditioned by the isolation of speech communities, has been explored with the use of artificial network structures. The study considers the sparse plantations and the stratification of society, which are typical to a lot of colonies. The model has simulated the emergence of lexical items from innovation and adaption from the substrate language and the minority language in creole in a complex social ecology. The thesis offers insights into the role of social factors in the evolution of language with reference to the empirical observation from the scholarship of language contact. The exploratory model presented in the thesis offers a schema for further investigation into how linguistic phenomena can emerge from social interaction in a controlled experiment which would have otherwise been difficult to conduct in real world.