Evolution of Language: An Agent-Based Simulation

Dr. Mark Dras
Macquarie University

Tuesday, August 28, 2001
1:00 p.m. 
302 Heller Hall

Abstract

Languages change continuously, in terms of their phonology, morphology and 
syntax: they can mutate in isolation, split off and diverge, or be 
affected by other languages. This happens because languages are not just 
cognitive systems but are conditioned by social interactions, making them 
dynamical systems as well, similar to biological and physical systems. 
There are typical patterns of change that occur in these systems, with 
change starting off slowly, accelerating, then slowing again; moreover, 
this change takes place over several generations. There are only a few 
previous attempts to model language change, and these either impose the 
form of the change onto the model or give empirically inaccurate results.

We take a particular language phenomenon, vowel harmony in Turkic 
languages, and model that using an agent-based simulation implemented 
through a set of Swarm libraries available for Java and Objective C. In 
the simulation the agents are endowed with low-level preferences and 
linguistic and social behaviors. We show that empirically-observed 
patterns of change are an emergent property of the model, in that they 
arise naturally, but without prior specification, from the interactions of 
the agents.

Bio

Mark Dras got his PhD, in computer science, from Macquarie University in 
Sydney, Australia, in 1999. He has just finished a two-year postdoc at the 
Institute for Research in Cognitive Science at the University of 
Pennsylvania, and is heading back to Australia. His research interests 
center around models of language transformations, and include formal and 
mathematical properties of synchronous grammars, machine translation, and 
language evolution.