Systematicity between Forms and Meanings across Languages Supports Efficient Communication

TL;DR

This paper investigates how languages balance simplicity and accuracy in expressing grammatical meanings, revealing systematic patterns that support efficient communication and are captured by a novel complexity measure.

Contribution

It introduces a new complexity measure based on learnability, linking efficient communication theory to linguistic systematicity across diverse languages.

Findings

Verbs and pronouns are shaped by pressures for simplicity and accuracy.

The novel complexity measure better predicts attested language systems.

Systematicity in language supports efficient communication.

Abstract

Languages vary widely in how meanings map to word forms. These mappings have been found to support efficient communication; however, this theory does not account for systematic relations within word forms. We examine how a restricted set of grammatical meanings (e.g. person, number) are expressed on verbs and pronouns across typologically diverse languages. Consistent with prior work, we find that verb and pronoun forms are shaped by competing communicative pressures for simplicity (minimizing the inventory of grammatical distinctions) and accuracy (enabling recovery of intended meanings). Crucially, our proposed model uses a novel measure of complexity (inverse of simplicity) based on the learnability of meaning-to-form mappings. This innovation captures fine-grained regularities in linguistic form, allowing better discrimination between attested and unattested systems, and establishes a new connection from efficient communication theory to systematicity in natural language.