Alien forms for alien language: investigating novel form spaces in cultural evolution

Christine Cuskley

doi:10.1057/s41599-019-0299-5

Christine Cuskley

Open Access

https://doi.org/10.1057/s41599-019-0299-5

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Abstract

A cornerstone of experimental studies in language evolution has been iterated artificial language learning: studies where participants learn of artificial ‘alien’ languages, and the product of their learning is then passed onto other participants successively. Results over the last decade show that some defining features of human language can arise under these experimental conditions, which use iteration to simulate processes of cultural transmission. The form modalities used in iterated learning studies have expanded considerably in recent years, but the dynamics of how learning a completely novel form system interact with processes of cultural transmission are only beginning to be explored. This paper provides a brief overview of artificial language learning studies in the context of language evolution, situating them in a framework which focuses on forms used in learning and production. This issue is further explored with an iterated experiment which focuses on the role of learning completely novel forms in isolation. This experiment uses a new set of graphical symbols called Ferros, which are produced using a virtual palette. Results show that properties of this novel form space—in particular, ease of articulation—have specific effects on sequence learning and evolution. These results have implications for how forms and modalities might constrain language systems, and demonstrate how the use of truly novel alien forms might be extended to address new questions in cultural and linguistic evolution.

Highlights

Over the last two decades, cultural evolution has emerged as a framework with relevant insights into fields ranging from biology (Mesoudi, 2007) to art history (Sigaki et al 2018), and notably, linguistics
Evolutionary linguistics was an early adopter of a cultural evolutionary framework: many concepts central to cultural evolution have been at the core of historical linguistics and language change for decades (Croft, 2006)
While historical linguistics and language change have been vibrant for centuries, the study of language evolution was relatively fallow for most of the twentieth century, following the famous ‘ban’ on studying the evolution of language from the Paris linguistic society (Christiansen and Kirby, 2003); see notable contributions such as Hockett (1960) and Hewes et al (1973)

Summary

Introduction

Over the last two decades, cultural evolution has emerged as a framework with relevant insights into fields ranging from biology (Mesoudi, 2007) to art history (Sigaki et al 2018), and notably, linguistics. Given limitations on form complexity, these results suggest that constraints on ease of production are likely to form the strongest pressures on structure: the tetrominoes are likely to emerge because producing forms of adjacent cells is less effortful than selecting four non-adjacent cells (Claidière et al 2014; note that they did not explicitly measure this) Both of these studies use relatively simple form spaces. Ferros with small articulation spaces have higher surprisal, while those with large articulation spaces have low surprisal6 For each of these measures, we tested whether generation and initial condition affected the outcomes using linear mixed effects models. The entropy was calculated across all the Ferros produced by each participant as in Eq (1), where i is the probability of each Ferro occuring in the set produced by the participant: HðXÞ

À pðxiÞlog

Findings

Discussion