Are top-cited papers more interdisciplinary?

Over the last decade, the relationship between interdisciplinarity and scientific impact has been the focus of many bibliometric papers, with diverging results. This paper aims at contributing to this body of research, by analyzing the level of interdisciplinarity, compiled with the Simpson Index, of the top 1% most highly cited papers and of papers with lower citation percentile ranks. Results shows that the top 1% most cited papers exhibit higher levels of interdisciplinarity than papers in other citation rank classes and that this relationship is observed in more than 90% of NSF specialties. This suggest that interdisciplinary research plays a more important role in generating high impact knowledge.