A study led by McGill University researchers challenges the theory that language change over time requires new generations to replace older generations of speakers. Rather, when words change meaning, speakers of all ages participate; while older speakers might take two or three years longer than their younger colleagues to adopt new word usage, in some cases they lead the way in introducing new word meanings into the common vocabulary, the researchers found.

"This runs counter to general beliefs about how language evolves over time," said Gaurav Kamath, a Ph.D. student in Linguistics at McGill and the lead author on the paper published recently in the Proceedings of the National Academy of Sciences. The researchers reached their conclusion after using AI models to analyze changes in the use of more than 100 words found in 7.9 million U.S. Congressional speeches given between 1873 and 2010 by several thousand different speakers.

While it was difficult for the researchers to identify a new meaning of a word as it emerged, once a new meaning for a word was well established, they were able to look backward to see when it first appeared and to trace shifts in meanings over time.

For instance, the term "article" to refer to a part of a bill or law was a constant throughout the period 1873 to 2010. However, the use of "article" to refer to objects, while common until the 1940s, was much less so by the 1950s. Since about the 1970s, it has mainly referred to news stories.

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