Amount of Learning and Signal Stability Modulate Emergence of Structure and Iconicity in Novel Signaling Systems

Vera Kempe,Nicolas Gauvrit,Monica Tamariz,Sheila Cunningham,Nikolay Panayotov

doi:10.1111/cogs.13057

Vera Kempe, Nicolas Gauvrit + Show 3 more

Open Access

https://doi.org/10.1111/cogs.13057

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Abstract

Iterated language learning experiments that explore the emergence of linguistic structure in the laboratory vary considerably in methodological implementation, limiting the generalizability of findings. Most studies also restrict themselves to exploring the emergence of combinatorial and compositional structure in isolation. Here, we use a novel signal space comprising binary auditory and visual sequences and manipulate the amount of learning and temporal stability of these signals. Participants had to learn signals for meanings differing in size, shape, and brightness; their productions in the test phase were transmitted to the next participant. Across transmission chains of 10 generations each, Experiment 1 varied how much learning of auditory signals took place, and Experiment 2 varied temporal stability of visual signals. We found that combinatorial structure emerged only for auditory signals, and iconicity emerged when the amount of learning was reduced, as an opportunity for rote‐memorization hampers the exploration of the iconic affordances of the signal space. In addition, compositionality followed an inverted u‐shaped trajectory raising across several generations before declining again toward the end of the transmission chains. This suggests that detection of systematic form‐meaning linkages requires stable combinatorial units that can guide learners toward the structural properties of signals, but these combinatorial units had not yet emerged in these unfamiliar systems. Our findings underscore the importance of systematically manipulating training conditions and signal characteristics in iterated language learning experiments to study the interactions between the emergence of iconicity, combinatorial and compositional structure in novel signaling systems.

Highlights

The last two decades have seen a vast expansion of experimental research into the cultural evolution of language
In these iterated language learning experiments, participants are presented with novel signals for a set of meanings that they have to learn and—in some instances—use in referential communication with a partner
The findings have demonstrated that passing languages through an inter-generational transmission bottleneck while using them for intra-generational communication leads to the emergence of artificial mini-languages that are increasingly easier to learn and more systematically structured in ways that resemble natural languages

Summary

Introduction

The last two decades have seen a vast expansion of experimental research into the cultural evolution of language. The incompatibility of language evolution and psychological testing time scales may seem to render any laboratory research that tries to address these questions futile. Building on seminal work by Bartlett (1932) and Esper (1966), recent methodological advances have utilized iterated learning in increasingly creative and sophisticated ways to gain insights into the fundamental principles that underpin the emergence of linguistic structure. In these iterated language learning experiments, participants are presented with novel signals for a set of meanings that they have to learn and—in some instances—use in referential communication with a partner. It should be noted that compositionality can emerge without generational transmission, for instance, during communication in large social networks (Raviv, Meyer, & Lev-Ari, 2019) or when the predictability of referents from the context is low (Winters, Kirby, & Smith; 2018)

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