This paper enquires into the grounds for convergence of judgements in a situation of blind peer review, where reviewers are asked to assess the standing of scholars in a disciplinary field. The paper first considers traditional accounts of peer review and threats to its reliability and validity. Next it examines the grounds for disciplinary sociality and different forms of expertise that stratify the disciplinary field. The paper will report the results of an initial study of peer review judgements in the disciplines of Law, Psychology and Historical Studies. The paper will conclude by assessing the variable merits of micro- and macro-sociological explanations in accounting for the phenomenon of convergent disciplinary judgements. A case will be made for the explanatory power of social norms. (Contains 2 figures and 2 tables.)