In 2009, Americans celebrated the first African American president and female speaker of the House in history. This illustrates the progress that women and minorities have made in attaining leadership positions historically occupied by White men.However, there are reasons to suspect that inspiring biographies and optimistic demographic statistics disguise the fragility of the gains made by individuals in stereotype-incongruent occupations. Numerous studies have documented the ways in which counterstereotypical individuals are discriminated against (Eagly & Karau, 2002; Glick, Zion, & Nelson, 1988). In addition to hitting the “glass ceiling” impeding their rise to top leadership roles, women often find themselves poised on a “glass cliff”―meaning that they are more likely than men to fall from their position (Ryan & Haslam, 2005).In the research reported here, the authors examined one potential mechanism for glass-cliff effects—specifically, that making small mistakes on the job is particularly damaging to individuals in gender-incongruent occupations. Stereotyping thrives on ambiguity. Although minorities with unambiguously strong qualifications are often evaluated fairly, when qualifications are ambiguous, stereotypes strongly influence judgments (Gaertner & Dovidio, 1986).Thus, a Black job candidate with a stellar record will receive high evaluations, but a Black candidate with a mixed record will face discrimination when compared with a White candidate (Hodson, Dovidio, & Gaertner, 2002). Thus, the authors predicted that when an individual has achieved a high-status position in a gender-incongruent occupation, making a mistake can prove especially damaging to his or her status. A gender-congruent leader’s competence is assumed, but for a gender-incongruent leader, salient mistakes create ambiguity and call the leader’s competence into question, which, in turn, leads to a loss of status.The authors hypothesized that this effect is driven by reactions to individuals in roles inconsistent with their gender—and not simply by discrimination against women—and we predicted that a similar penalty would be evident for men and women in gender-incongruent jobs.