Linguistic Dating and Glottochronology
Attempts to assign dates to language splits, including the lexicostatistical method of glottochronology and the serious criticisms it has attracted.
Definition
Glottochronology is a lexicostatistical method that estimates the time depth of language divergence from the proportion of shared cognate basic vocabulary, assuming a roughly constant rate of vocabulary replacement.
Scope
This topic covers methods for establishing relative and absolute chronologies of language divergence. It centers on lexicostatistics (measuring shared basic vocabulary to gauge relatedness) and glottochronology (using assumed replacement rates to estimate dates of divergence), together with the major criticisms of the constant-rate assumption and modern computational and Bayesian alternatives.
Core questions
- How can the time of a language split be estimated from linguistic evidence?
- What assumptions underlie glottochronology, and why are they contested?
- What is the difference between lexicostatistics and glottochronology?
- Why do most historical linguists distrust absolute glottochronological dates?
- How do modern computational and Bayesian phylogenetic methods relate to older dating approaches?
Key theories
- Glottochronology and the constant-rate assumption
- Swadesh proposed that core vocabulary is replaced at an approximately constant rate, so the share of cognates between two languages can be converted into a date of divergence; this rests on a contested uniform-rate assumption.
History
Morris Swadesh developed lexicostatistics and glottochronology in the early 1950s, proposing standardized basic-vocabulary lists. Bergsland and Vogt's 1962 study showed that observed replacement rates varied widely across documented cases, undermining the constant-rate assumption. The approach fell out of favor, though computational phylogenetic methods have revived interest in dating divergence by different means.
Debates
- Validity of the constant replacement rate
- Bergsland and Vogt demonstrated that vocabulary replacement rates are not constant across languages, so glottochronological dates are unreliable; defenders argue refined methods can partly address this.
Key figures
- Morris Swadesh
- Knut Bergsland
- Hans Vogt
Related topics
Seminal works
- swadesh1952
- bergsland1962
Frequently asked questions
- What is a Swadesh list?
- A Swadesh list is a standardized list of basic, culturally neutral vocabulary items (such as body parts, numerals, and natural phenomena) used in lexicostatistics to compare languages.
- Do linguists accept glottochronological dates?
- Most are skeptical of absolute dates from classical glottochronology because the assumption of a constant replacement rate has been shown to be false; relative chronologies from the comparative method are more trusted.