Researchers commonly refer to peer review as the “gold standard,” which makes it seem as if a peer-reviewed paper — one sent by journal editors to experts in the field who assess and critique it before publication — must be legitimate, and one that’s not reviewed must be untrustworthy. But peer review, a practice dating to the 17th century, is neither golden nor standardized. Studies have shown that journal editors prefer reviewers of the same gender, that women are underrepresented in the peer review process, and that reviewers tend to be influenced by demographic factors like the author’s gender or institutional affiliation. Shoddy work often makes it past peer reviewers, while excellent research has been shot down. Peer reviewers often fail to detect bad research, conflicts of interest and corporate ghostwriting.