Why is language well-designed for communication? (Commentary on Christiansen and Chater: 'Language as shaped by the brain')

TL;DR

This paper critiques the idea that iterated learning uniquely explains language's communicative efficiency, highlighting its inability to account for certain linguistic features that may trade off learnability for communication.

Contribution

It challenges the sufficiency of iterated learning as an explanation for language design, emphasizing the need to consider other factors like universal grammar.

Findings

Iterated learning explains language efficiency no better than non-functional accounts.

It does not predict features like central embedding or large lexicons.

Some language features may prioritize communication over learnability.

Abstract

Selection through iterated learning explains no more than other non-functional accounts, such as universal grammar, why language is so well-designed for communicative efficiency. It does not predict several distinctive features of language like central embedding, large lexicons or the lack of iconicity, that seem to serve communication purposes at the expense of learnability.