Evolving language compositionality in a frequency-structured meaning space
2026-07-31 • Computation and Language
Computation and Language
AI summaryⓘ
The authors studied how languages evolve when passed from one person to another, focusing on how often different meanings appear. They found that common meanings can avoid being part of the grammar that other, less common meanings follow, similar to real languages. However, if frequency is assigned to smaller parts instead of whole meanings, the language doesn't transmit well between generations. This suggests that frequency helps shape language only when learners see meanings as whole units, not broken into smaller elements.
iterated learning modellanguage evolutioncompositionalitylanguage acquisitionfrequency distributionlanguage transmissionform-meaning unitslanguage learning bottleneck
Authors
Fabio De Ponte, Eloise Gaines-White, Conor Houghton, Seth Bullock
Abstract
The iterated learning model was introduced to investigate language evolution: the way in which the characteristic properties of human languages have been shaped, at least partly, by repeated transmission from one language user to another. The key finding is that language compositionality can arise spontaneously as a consequence of language being passed repeatedly through a language learning bottleneck. Here we explore how changing the frequency of different meanings, so that some meanings occur much more frequently than others, affects the character of its compositionality. We find that, as observed in natural languages, high-frequency meanings can escape the pressure to conform to the grammar that characterizes lower-frequency meanings. However, when the frequency structure is instead imposed on parts rather than on whole meaning vectors, the language fails to transmit across generations. This occurs despite the fact that the most frequent elements are reliably learned. These results suggest that frequency can shape emergent linguistic structure only when the frequency distribution is defined over form-meaning units that learners can acquire holistically. When frequency is instead distributed over smaller units, it fails to support the relational structure required for compositional generalisation, thereby preventing stable language transmission.