The utterance selection model and the cultural evolution of languages
Jérôme Michaud (Edinburgh)
Tuesday 24 May 2016, 11:00–12:30
1.17 Dugald Stewart Building
In this talk, I discuss the cultural evolution of languages in the light of the utterance selection model (USM) for language change developed in 2006 by Baxter et al.
I start by discussing the process of cultural evolution in general and then recall the USM definition. This is a relatively simple agent-based model simulating the communicative interactions between interconnected agents on a network. Since a language can be defined at the population level, it is important to be able to understand the dynamics of the complete population. I present a stochastic (heterogeneous) mean field approximation of the USM that allows me to discuss the influence of different parameters, such as the connectivity of agents, the rate of production error, the learning rate, the importance of different agents and the size of the population. I show that the global behaviour of the population can be mainly understood in terms of two independent parameters and that there is a critical parameter at which the behaviour of the of the population qualitatively changes.
To complete the discussion, I introduce a modification of this model that includes a mechanism for agents to explicitly develop preferences for particular variants and investigate the consequences of this modification.