Expressive Punctuation and Subjective Adjectives in Biomedical Abstracts for Scholarly Communication

Abstracts of academic publications are central instruments of scholarly communication to summarize research findings. In addition, they can signal authors' stance and evaluation. This study examined how small markers of feeling and stance appear in biomedical abstracts, focusing on expressive punctuation marks and subjective adjectives. We analyzed 23,621,448 PubMed abstracts from journal articles published by 2026, identifying selected expressive punctuation marks, such as "!" and "?", and subjective participial adjectives, such as "interested" and "surprising". We then explored their temporal patterns and associations with country of affiliation, authorship, and journal impact factor. We found that these terms were uncommon but far from absent. Question marks appeared in 0.64% of abstracts and exclamation marks in 0.03%. Several markers of curiosity, enthusiasm, and surprise increased over recent decades. Abstracts with East Asian affiliations generally contained fewer such terms, whereas exclamatory usage was most common among abstracts with affiliations in India, and a question mark and subjective adjectives were more common among abstracts with Western affiliations. Abstracts from articles with fewer authors were generally more likely to include expressive punctuation marks and subjective adjectives. Abstracts with inferred female authors, especially inferred female last authors, were more likely to contain "!", "?", "interested", and "surprised". Conversely, "excited", "exciting", "interesting", and "surprising" were more common in abstracts with inferred male authors. Exclamation marks, question marks, "interested", and "interesting" were less prevalent in high-impact journals, whereas "shocked" and "surprising" were more prevalent in these journals. These findings suggest that subjective descriptions in scientific writing can reflect broader norms of scholarly communication. Such markers may serve as prompts for considering how abstracts frame novelty, uncertainty, and importance, thereby helping improve scholarly communication.