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Complex Adaptive Systems and the Origins of Adaptive Structure: What Experiments Can Tell Us


  • Hannah Cornish is funded by an ESRC postgraduate studentship. Monica Tamariz was funded by a Leverhulme Early Career Fellowship. Monica Tamariz and Simon Kirby are supported by ESRC Grant Number RES-062-23-1537 and by AHRC Grant Number AH/F017677/1. The work presented here benefited from discussion among the members of the University of Edinburgh's Language Evolution and Computation Research Unit, and constructive comments from two anonymous referees.

concerning this article should be addressed to Simon Kirby, Language Evolution and Computation Research Unit, The University of Edinburgh, 3 Charles Street, Edinburgh, EH8 9AD, UK. Internet:


Language is a product of both biological and cultural evolution. Clues to the origins of key structural properties of language can be found in the process of cultural transmission between learners. Recent experiments have shown that iterated learning by human participants in the laboratory transforms an initially unstructured artificial language into one containing regularities that make the system more learnable and stable over time. Here, we explore the process of iterated learning in more detail by demonstrating exactly how one type of structure—compositionality—emerges over the course of these experiments. We introduce a method to precisely quantify the increasing ability of a language to systematically encode associations between individual components of meanings and signals over time and we examine how the system as a whole evolves to avoid ambiguity in these associations and generate adaptive structure.