Cultural Evolution and Perpetuation of Arbitrary Communicative Conventions in Experimental Microsocieties

Christine A Caldwell,Kenny Smith

doi:10.1371/journal.pone.0043807

Christine A Caldwell, Kenny Smith

Open Access

https://doi.org/10.1371/journal.pone.0043807

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Journal: PloS one	Publication Date: Aug 23, 2012
Citations: 84	License type: CC BY 4.0

Affiliation: University of Stirling, University of Edinburgh

Abstract

Previous studies have shown that iconic graphical signs can evolve into symbols through repeated usage within dyads and interacting communities. Here we investigate the evolution of graphical signs over chains of participants. In these chains (or “replacement microsocieties”), membership of an interacting group changed repeatedly such that the most experienced members were continually replaced by naïve participants. Signs rapidly became symbolic, such that they were mutually incomprehensible across experienced members of different chains, and new entrants needed to learn conventionalised meanings. An objective measure of graphical complexity (perimetric complexity) showed that the signs used within the microsocieties were becoming progressively simplified over successive usage. This is the first study to show that the signs that evolve in graphical communication experiments can be transmitted to, and spontaneously adopted by, naïve participants. This provides critical support for the view that human communicative symbols could have evolved culturally from iconic representations.

Highlights

Human language exhibits a number of unique features which account for its unparalleled expressivity and efficiency as a system of communication, the most remarkable of these being systematic compositionality and arbitrariness
The results clearly indicate that arbitrary and contrasting conventions were established within microsocieties, and that these were transmitted to naıve newcomers to the group who themselves had played no part in negotiating the usage of that particular sign. This was apparent through measures of the simplicity and efficiency of the communication, and through comparison of the accuracy of the matchers when guessing the meanings of drawings completed by a member of their own group, compared with those completed by members of other microsocieties
The data on accuracy generated in the test phase in the final round provide the clearest evidence that arbitrary conventions had been established and were being faithfully transmitted

Summary

Introduction

Human language exhibits a number of unique features which account for its unparalleled expressivity and efficiency as a system of communication, the most remarkable of these being systematic compositionality (the meaning of a complex signal is [usually] a function of the meaning of its parts and the way in which they are combined [1]) and arbitrariness. Compositionality has been proposed to have developed from communication that was initially unsystematic and non-compositional, as a consequence of pressures for generalizability inherent in language transmission [3,4]. 220) over historical time, with more naturally meaningful communication, such as pantomimed gestures, as the likely origins. If these unique and universal features of human language can be shown to arise spontaneously from initially unsystematic and non-arbitrary communication, this suggests that the existence of such features is more likely the outcome of general mechanisms for learning and social cognition, in combination with repeated social transmission, rather than the consequence of an innate, specialised language faculty (see [7,8], for elaboration of this debate)

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