How communicatively optimal are exact numeral systems? Once more on lexicon size and morphosyntactic complexity

TL;DR

This paper evaluates the efficiency of exact recursive numeral systems across diverse languages, revealing many are less optimal than expected, which impacts understanding of linguistic evolution.

Contribution

It introduces a new annotation scheme for morphosyntactic complexity and provides a cross-linguistic analysis of numeral system efficiency.

Findings

Many languages are less efficient than expected in their numeral systems.

Predictable and unpredictable allomorphy affect numeral system complexity.

Implications for linguistic evolution and the design of numeral systems.

Abstract

Recent research argues that exact recursive numeral systems optimize communicative efficiency by balancing a tradeoff between the size of the numeral lexicon and the average morphosyntactic complexity (roughly length in morphemes) of numeral terms. We argue that previous studies have not characterized the data in a fashion that accounts for the degree of complexity languages display. Using data from 52 genetically diverse languages and an annotation scheme distinguishing between predictable and unpredictable allomorphy (formal variation), we show that many of the world's languages are decisively less efficient than one would expect. We discuss the implications of our findings for the study of numeral systems and linguistic evolution more generally.