Extant theory suggests that candidates with an unfocused identity – those spanning different categories - suffer from a valuation penalty because evaluators are confused by their profile, and concerned they lack the required skills. We argue that unfocused candidates may be penalized for another reason: they threaten established social boundaries. This happens in contexts where evaluators act as gatekeepers for social entities such as professions. We test how the penalty applied to unfocused candidates varies in an academic accreditation process, a setting where evaluators decide on admitting candidates to an academic discipline and where candidates’ prior performance is observable. We find, using data on the 2012 national scientific qualification in Italian academia, that the valuation penalty applied to unfocused (multi-disciplinary) candidates was most pronounced for the most high-performing candidates. High-performing yet ill-fitting candidates threaten the distinctiveness and knowledge domain of the discipline and are hence penalized by evaluators. High-performing multidisciplinary candidates suffered the greatest penalty in small and distinctive academic disciplines and when accreditors were highly typical members of their discipline. Our theory and findings suggest that the categorical imperative may not only be driven by cognitive or capability considerations, as typically argued in the literature, but also by attempts to maintain social boundaries.