Definition

Noun: 1. A method in historical linguistics that attempts to estimate the time depth at which two or more related languages diverged from a common ancestral language. It is based on the assumption that core vocabulary changes at a relatively constant rate over long periods.

Examples of Usage

• The linguist used glottochronology to propose a timeline for the divergence of the Polynesian languages.
• While controversial, glottochronology provided a rough estimate for when the ancestor of the Germanic languages split from Proto-Indo-European.
• Her research paper critically examined the assumptions underlying glottochronology.

Advanced Usage

• Glottochronological (adjective): Pertaining to or derived from glottochronology.
  • The glottochronological data suggested a separation around 2,500 years ago.
• The method is often discussed in contrast with or as a complement to the comparative method, which establishes relationships but not necessarily precise dates.

Variants and Related Words

• Lexicostatistics: Often used interchangeably with glottochronology, though some linguists distinguish lexicostatistics (measuring lexical similarity) as the first step that provides data for glottochronological (time-depth) calculations.

Synonyms

• Lexicostatistical dating
• Linguistic dating

Notes on Meaning

• The core principle involves calculating the percentage of cognates (words with a common origin) in a standardized list of basic vocabulary (e.g., the Swadesh list) between two languages. A lower percentage of shared cognates implies a longer period of separation.
• It is important to note that glottochronology is a controversial and often criticized technique within linguistics. Many scholars question the fundamental assumption of a constant rate of vocabulary replacement across all languages and contexts. Therefore, its results are typically viewed as highly speculative approximations rather than definitive dates.

Noun

1. the determination of how long ago different languages evolved from a common source language
   • he mapped the glottochronology of the Romance languages