How does age impact understanding of epistemic adverbs in health communication?

Objective: Not much is known about how one's understanding of words may differ with age. Here we explore how epistemic adverbs - as used in health communication to indicate degrees of uncertainty and risk - are understood by older and younger monolingual speakers of Australian English. Methods: We used an online dissimilarity rating task with sentence pairs presented as first and second doctor opinions which differed only with respect to the embedded epistemic adverbs (e.g., This could certainly cause some cramps vs. This could possibly cause some cramps). To evaluate the possible effect of age, we compared the dissimilarity ratings of older and younger Australian English monolinguals (aged >55 (n = 24) and aged 18-50 (n = 57), respectively). The data were interpreted using classical Multi-Dimensional Scaling (C-MDS) analysis, complemented by cultural consensus analysis and hierarchical cluster analysis. Results: Analyses revealed intragroup consensus for each speaker group. Both speaker groups clustered the hearsay adverbs (apparently, presumably, reportedly, and supposedly) similarly, and showed a similar understanding of probably, as reflected in a unique - albeit the least stable - cluster. Interestingly, the speakers differed in their understanding of high confidence adverbs and adverbs of likelihood. While they all clustered likely and possibly together, the older speakers also included certainly. Conclusions: Our analysis showed some differences in how epistemic adverbs are understood by older and younger Australian English speakers, suggesting that, between generations, there were subtle changes in the degree of certainty associated with some of the epistemic adverbs (e.g., certainly). When consulting with their patients, health practitioners should be mindful that the meaning they intend when using epistemic adverbs may not be shared by their patients, especially when there is an age gap between interlocutors. (c) 2025 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)