Which of the following statements is true regarding the responsibilities of a reviewer?

The statement about a reviewer's conflict of interest needing to be disclosed to the journal editor or grant agency is indeed true and reflects a central tenet of responsible conduct in research and peer review. When a reviewer has a conflict of interest—whether it be financial, personal, or professional—it can influence their judgment and the integrity of the review process. Therefore, transparency is essential; by disclosing such conflicts, reviewers help ensure that the peer review process remains fair and impartial. This disclosure is critical for maintaining the trust of the research community and ensuring that decisions about publications or funding are made based on merit rather than bias or personal gain.

The other statements imply incorrect practices. Focusing only on positive aspects can lead to an incomplete assessment of the manuscript, depriving the authors and readers of constructive criticism that can enhance research quality. Promoting one's own research as a primary responsibility goes against the objective nature of peer review, which should prioritize assessing the work of others impartially. Finally, failing to disclose personal biases undermines the integrity of the review process and can affect the reputation of the journal or funding agency involved.