We analyze the dynamic properties of 107 words recorded in English, Spanish and Hebrew over the period 1800–2008 in order to gain insight into the coevolution of language and culture. We report language independent patterns useful as benchmarks for theoretical models of language evolution. A significantly decreasing (increasing) trend in the birth (death) rate of words indicates a recent shift in the selection laws governing word use. For new words, we observe a peak in the growth-rate fluctuations around 40 years after introduction, consistent with the typical entry time into standard dictionaries and the human generational timescale. Pronounced changes in the dynamics of language during periods of war shows that word correlations, occurring across time and between words, are largely influenced by coevolutionary social, technological, and political factors. We quantify cultural memory by analyzing the long-term correlations in the use of individual words using detrended fluctuation analysis.
How many words are in the English language? The paper gave the best-yet estimate of the true number of words in English—a million, far more than any dictionary has recorded (the 2002 Webster’s Third New International Dictionary has 348,000). More than half of the language, the authors wrote, is “dark matter” that has evaded standard dictionaries.
The paper also tracked word usage through time (each year, for instance, 1% of the world’s English-speaking population switches from “sneaked” to “snuck”). It also showed that we seem to be putting history behind us more quickly, judging by the speed with which terms fall out of use. References to the year “1880” dropped by half in the 32 years after that date, while the half-life of “1973” was a mere decade.
Finally, the authors identified a universal “tipping point” in the life cycle of new words. Roughly 30 to 50 years after their birth, words either enter the long-term lexicon or fall off into oblivion. How that’s for a half-life?
(via Wall Street Journal)