We analyze how subjects' self-assessment depends on whether its accuracy is observable to others. We find that women downgrade their self-assessment given observability while men do not. Women avoid the shame they may have if others observe that they overestimated themselves. Men, however, do not seem to be similarly shame-averse. This gender difference may be due to different societal expectations: While we find that men are expected to be overconfident, women are not. Shame-aversion may explain recent findings that women shy away from competition, demanding jobs and wage negotiations, as entering these situations shows a certain confidence of one's ability.