Implicit bias is strongest when assessing top candidates

BackgroundAcademic life is highly competitive and expectations of fair competition underlie the assumption that academia is a meritocracy. However, implicit bias reinforces gender inequality in all peer review processes, unfairly eliminating outstanding individuals and depleting academia of diversity. Here, we ask whether applicant gender biases reviewer assessments of merit in Sweden, a country that is top ranked for gender equality. MethodsWe analyzed the peer review procedure for positions awarded at a Swedish medical University, Karolinska Institutet (KI), during four consecutive years (2014-2017) for Assistant Professor (n=207) and Senior Researcher (n=153). We derived a composite bibliometric score to compute productivity, and compared this to subjective external (non-KI) peer reviewer scores on applicants merits to test their association for men and women, separately. ResultsMen and women with equal merits are not scored equally by reviewers. Men generally have stronger associations (steeper slopes) between computed productivity and subjective external scores, meaning that peer reviewers suitably "reward" mens productivity with increased merit scores. However, for each additional composite bibliometric score point, women applying for Assistant Professor positions only receive 58% (79% for Senior Researcher) of the external reviewer score that men received, confirming that implicit bias affects external reviewers assessments. As productivity increases, the difference in merit scores between men and women increases. ConclusionsAccumulating bias impacts most strongly in the highest tier of competition, the pool from which successful candidates are ultimately chosen. Gender bias is apparent in external peer review processes of applications for academic positions in Sweden, and is likely to reinforce the unbalanced numbers of professorships in Sweden.