<p>Colleges and universities across the globe have implemented a variety of bureaucratic reforms aimed at diversification of the professoriate. Initiatives related to bias, such as implicit bias training, are especially common, reflecting an assumption that underrepresentation of women and racialized minorities in academe originates from biased evaluative processes. To date, however, existing research lacks representative data assessing the extent to which members of the academic profession attribute insufficient diversity to bias in hiring and promotion. Drawing on a survey of 1,923 physicists and biologists in the United States, the United Kingdom, Italy, and India, we examine the extent to which scientists believe that insufficient diversity in science reflects bias in hiring and promotion. The results demonstrate that perceptions of bias are related to gender, race, political ideology, and national context. We consider the practical implications of these findings alongside evidence from organizational theory that demonstrates how the effects of diversity training are often short-lived and counterproductive.</p>