At a Glance
- Researchers analyzed 7.9 million U.S. Congressional speeches from 1873 to 2010 to study how word meanings change and who adopts those changes.
- The study challenges the belief that language evolution is purely generational, where only the young introduce innovations while older generations resist them.
- Using AI, scientists found that older speakers, while sometimes slightly slower, readily adopt new word usages within just a few years of their younger colleagues.
- This finding suggests that meaning change is a “zeitgeist” phenomenon, meaning speakers of all ages participate in linguistic shifts at roughly the same time.
- Future research aims to see if these patterns of rapid adoption by all age groups hold true in more socially diverse populations beyond politicians.
A new study challenges the long-held belief that language changes primarily because new generations of speakers replace older ones. Instead, researchers from McGill University found that when a word’s meaning shifts, speakers of all ages tend to adopt the new usage. The findings suggest that while older adults may be slightly behind their younger counterparts, they adapt quickly, indicating language evolution is a shared phenomenon rather than a process strictly divided by age.
To reach this conclusion, the researchers conducted a large-scale study, analyzing an immense dataset of over 7.9 million U.S. congressional speeches delivered between 1873 and 2010. They employed artificial intelligence, specifically language model-based “word sense induction,” a method that allows a computer to identify and distinguish between the different meanings, or senses, of a single word. By tracking over 100 words known to have changed over time, the team could model how the popularity of each word sense varied not just by year, but by the age of the speaker.
The results, published in the Proceedings of the National Academy of Sciences, show a small but significant effect of speaker age. This runs counter to the “generational” theory of language change, which posits that older speakers tend to conserve their habits while younger speakers innovate. Instead, the data support a “zeitgeist” model, where changes are adopted nearly universally. For example, the use of the word “article” to refer to a physical object declined after the 1940s, while its use to mean a news story increased after the 1970s, a shift that occurred across all age groups in the study.
“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 paper’s lead author, in a university press release. While the study provides powerful new insights, the authors note that politicians are not a fully representative group of speakers. The next step is to investigate whether these findings apply to more diverse social groups and different types of language, such as the fast-evolving slang used by today’s teenagers.
References
- Boucher, A. & McGill University. (2025, August 4). Analysis of more than a century’s worth of political speeches challenges theory about how linguistic usage evolves. Phys.Org; McGill University. https://phys.org/news/2025-08-analysis-century-worth-political-speeches.html
- Kamath, G., Yang, M., Reddy, S., Sonderegger, M., & Card, D. (2025). Semantic change in adults is not primarily a generational phenomenon. Proceedings of the National Academy of Sciences, 122(31), e2426815122. https://doi.org/10.1073/pnas.2426815122
