Study Reveals Citation Bias in Peer Review Decisions

A recent preprint study has found evidence of citation bias in peer review: reviewers are more likely to recommend acceptance of a manuscript if it cites their own work.

The study analyzed peer review data from 18,400 manuscripts across four open-access publishing platforms. It showed that reviewers whose research was cited were significantly more inclined to endorse acceptance compared to those who were not cited. Specifically, when reviewers requested citations to their own work and authors complied, 92% of those reviewers subsequently recommended acceptance, compared with 76% among reviewers whose work was not cited. Conversely, if citation requests were ignored, those reviewers were roughly twice as likely to reject or withhold approval compared to offering direct acceptance.

The analysis also noted that reviewers requesting citations tended to use directive language such as “need” or “please” more often in rejection comments. However, some scholars caution that such phrasing does not necessarily indicate coercion, since citation suggestions may also reflect legitimate efforts to strengthen a manuscript's quality.

The authors acknowledge that distinguishing between “unreasonable demands” and “valid recommendations” remains challenging. To address this, they propose requiring reviewers to justify citation requests and suggest developing algorithmic tools to help editors detect and evaluate potentially coercive citation practices.