Gender and disciplinary differences in grant proposal peer review: Content and sentiment in 39,280 reports.

Peer review by experts is central to the evaluation of grant proposals, but little is known about how gender and disciplinary differences shape the content and tone of grant peer review reports. We analyzed 39,280 review reports submitted to the Swiss National Science Foundation between 2016 and 2023, covering 11,385 proposals for Project Funding across 21 disciplines from the Social Sciences and Humanities (SSH), Life Sciences (LS), and Mathematics, Informatics, Natural Sciences, and Technology (MINT). Using supervised machine learning, we classified over 1.3 million sentences by evaluation criteria and sentiment. Reviews in SSH were significantly longer and more critical, with less focus on the applicant's track record, while those in MINT were more concise and positive, with a greater focus on the track record, as compared to those in LS. Compared to male reviewers, female reviewers wrote longer reviews that more closely aligned with the evaluation criteria and expressed more positive sentiments. Female applicants tended to receive reviews with slightly more positive sentiment than male applicants. The tone, length, and focus of peer review reports varied systematically by applicant gender and disciplinary context. These differences have important implications for fairness and consistency in research funding.