When President Barack Obama picked Sonia Sotomayor for the U.S. Supreme Court, he suggested the judge's modest beginnings and bootstrap background would add immediacy and even empathy to her opinions. But neither legal smarts nor life lessons seemed foremost on Judge Sotomayor's mind when she reflected on her accomplishments. Her perspective on her trajectory? "I am always looking over my shoulder wondering if I measure up."
"Daunting" and "humbling" is how she described her nomination, while her first words at the podium were about being nervous. In her assessment, she is less like the supremely self-confident Mr. Obama, with whom she has often been compared, and more like many successful professional women whose obvious bona fides don't stop them from doubting themselves - even in public.
Social psychologists have known for decades that a large group of female high-achievers don't really believe they're as smart and accomplished as others think they are. Though they excel in public, they secretly feel like they're pretending. Dubbed the imposter phenomenon, many of these highly accomplished women privately attribute their achievements to chance events, and each time they move up a rung, they wonder when their luck will run out.
Take Margaret Chan, who, as head of the World Health Organization, is the world's most powerful public health official. Her policy directives contained outbreaks of avian flu in 1997 and SARS in 2003 and, more recently, she has been tackling H1N1. Yet, when asked by a New York Times reporter how she rose to her position, the superbly qualified Dr. Chan said it was all a matter of luck: She just happened to be at the right place at the right time.
Such disconnects between self-perception and reality don't cancel out these women's achievements. Nor do they make them any less deserving of their appointments. In fact, having less bluster can have the opposite effect, spurring those with less self-confidence to outstrip the competition by trying much harder.
When two Dublin cognitive scientists, Michelle Cowley and Ruth Byrne, looked at what distinguishes chess masters from mediocre players, they discovered that the most brilliant players constantly second-guess themselves. They look eight moves ahead and anticipate the worst. Novices, meanwhile, were more likely to be optimistic - and then experience crushing defeats. It turns out the experts are not bursting with self-confidence. They are self-doubters who hone their skills by countering their own hypotheses.
Of course, everyone doubts their abilities now and then, but evidence shows university-educated women are much better at it than men. According to research by two Purdue psychologists, Shamala Kumar and Carolyn Jagacinski, women are more likely than men to agree with the phrase, "I can give the impression that I am more competent than I really am."
Still, doubting yourself doesn't mean you're unequal to the task. The women who had the highest scores on the researchers' imposter scale were also eager to test themselves - to prove to themselves what everyone else already knew. This is how they bested their peers. And they were unlike the men in the comparison group, who, if they felt unsure of themselves, wouldn't enter contests they thought they might not win. "The motivation of the men was to avoid doing poorly, looking weak," Dr. Jagacinski said.
While Judge Sotomayor has played down her controversial "wise Latina" remarks made in a 2001 speech, she was right about one thing: Gender does make a difference in our judgments, especially our self-judgments. But, ultimately, it's not whether you think you're good that counts. It's whether you really are good.
Susan Pinker, a psychologist, is the author of The Sexual Paradox: Extreme Men, Gifted Women and the Real Gender Gap .