Languages: Evolution and frequency of word use

Why do some words evolve rapidly through time whilst others stay the same, often with an identical meaning in many different languages? Why do some English verbs remain stubbornly irregular, to the frustration of language learners worldwide?

Some words, such as ‘bird’ or ‘tail’, are expressed by dozens of unrelated word forms in different languages, whereas others, such as the number ‘three’ or the word for ‘water’, use the same word forms or ‘cognates’ across the whole Indo-European language family. This indicates that some words evolve more quickly than others, but until now no general mechanism has been proposed to explain why.

Mark Pagel and colleagues used a statistical modelling technique to analyse four Indo-European languages: English, Spanish, Russian and Greek, and compared this to a database of 200 fundamental vocabulary meanings in 87 languages. They found that across all 200 meanings, commonly used words, such as numbers, evolve much more slowly, suggesting that the frequency with which specific words are used affects their rate of replacement over thousands of years.

In a separate paper, Martin Nowak and colleagues present a quantitative study to measure the rate at which verbs in English have become more regular with time, and find that frequency of use also affects this relationship. The authors compiled a list of 177 irregular verbs from Old English, and found that only 98 are still irregular today. They then calculated the frequency of occurrence for each verb, and discovered that the less a verb is used, the faster it takes a regular form.

CONTACT

Mark Pagel (University of Reading, UK) Author paper [1]
Tel: +44 118 931 8900; E-mail: m.pagel@reading.ac.uk



Martin Nowak (Harvard University, Cambridge, MA, USA) Author paper [2]
Tel: +1 617 496 4737; E-mail: martin_nowak@harvard.edu



Tecumseh Fitch (University of St Andrews, UK) N&V author
Tel: +44 1334 462 054; E-mail: wtsf@st-and.ac.uk