We've all seen it: the employee who's convinced she's doing a great job and gets a mediocre performance appraisal, or the student who's sure he's aced an exam and winds up with a D.

The tendency that people have to overrate their abilities fascinates Cornell University social psychologist David Dunning, PhD. "People overestimate themselves," he says, "but more than that, they really seem to believe it. I've been trying to figure out where that certainty of belief comes from."

Dunning is doing that through a series of manipulated studies, mostly with students at Cornell. He's finding that the least competent performers inflate their abilities the most; that the reason for the overinflation seems to be ignorance, not arrogance; and that chronic self-beliefs, however inaccurate, underlie both people's over and underestimations of how well they're doing.

Meanwhile, other researchers are studying the subjective nature of self-assessment from other angles. For example, Steven Heine, PhD, a psychologist at the University of British Columbia, is showing that self-inflation tends to be more of a Western than a universal phenomenon. And psychologist Larry Gruppen, PhD, of the University of Michigan Medical School, is examining inaccurate self-assessments among medical students, where the costs of self-inflation can be particularly high (see related article).

Knowing thyself isn't easy

There are many reasons why it's hard to "know ourselves" in certain domains, Dunning says. In a subjective area like intelligence, for example, people tend to perceive their competence in self-serving ways. A student talented in math, for instance, may emphasize math and analytical skills in her definition of intelligence, while a student gifted in other areas might highlight verbal ability or creativity.

Another problem is that in many areas of life, accurate feedback is rare. People don't like giving negative feedback, Dunning says, so it's likely we will fail to hear criticism that would help us improve our performance.

"It's surprising how often feedback is nonexistent or ambiguous," he asserts. "It's a pretty safe assumption that what people say to our face is more positive than what they're saying behind our backs." People also overestimate themselves out of ignorance, Dunning says. Take the ironic example of an elderly man who thinks he's an excellent driver but is a hazard on the road, or the woman who reads a book about the stock market and is ready to compete with a professional stockbroker.

Dunning is addressing some of these self-overestimation issues empirically. In a series of studies reported in the December 1999 Journal of Personality and Social Psychology (Vol. 77, No. 6), he and co-author Justin Kruger, PhD, then a Cornell graduate student and now an assistant professor at the University of Illinois at Urbana-Champaign, examined the idea that ignorance is at the root of some self-inflation. Cornell students received short tests in humor, grammar and logic, then assessed how well they thought they did both individually and in relation to other Cornell students. In all three areas, students who performed the worst greatly overestimated their performance compared to those who did well.

In another article in the January issue of the Journal of Personality and Social Psychology (Vol. 84, No. 1), Dunning and Cornell doctoral candidate Joyce Ehrlinger describe four studies revealing a potential source of people's errors in self-judgment: their longstanding views of their talents and abilities. Depending on which measure the team looked at, such self-views were equally or more related to performance estimates than to their performance itself, and these self-views often produced errors in their reporting on how well they had just performed.

In one of the studies, for instance, the team tacitly pulled information from Cornell students to see if they thought they had logical ability. After that, the students took a multiple-choice test described as focusing on logical reasoning, then estimated the number of items they had answered correctly. Students who initially ranked themselves high on logical ability believed they were more likely to do well than those who rated themselves low on the ability, even when their performances ended up the same. Similarly in two other studies, the researchers manipulated students' chronic view of a particular talent by asking questions priming them to raise or lower their view of it. Depending on the questions, students became more or less optimistic about how well they did on a test of the talent, even though their performance was equal.

Dunning also has studied people's self-assessments in the moral domain and unearthed what he calls a "holier-than-thou" syndrome. In a series of studies reported in the December 2000 Journal of Personality and Social Psychology (Vol. 79, No. 6), he and Nicholas Epley, PhD, then a Cornell graduate student and now an assistant professor at Harvard University, found that undergraduates consistently overrated the likelihood that they would act in generous or selfless ways.

One of the studies, for example, uses a version of the classic "prisoners' dilemma" experiment, in which subjects must choose between self-interest and cooperation. In Dunning's study, 84 percent of the students initially predicted they would cooperate with their partner, but only 61 percent actually did. Furthermore, students' actual performance squared with their estimates of how others would behave, thus demonstrating a propensity to see others more accurately than they see themselves, Dunning comments.

Some critics have faulted Dunning's work for methodological problems, saying that it overstates the degree to which people overestimate their abilities. For example, in a 2002 article in Personality and Individual Differences (Vol. 33, No. 4), Georgia Institute of Technology psychologist Phillip Ackerman, PhD, and colleagues assert that Dunning fails to account for "regression to the mean," a statistical phenomenon which finds that if people are on the low end of a distribution, they will naturally rank themselves higher simply because their perceptions of ability aren't correlated with actual ability. In response, Dunning contends that he and Kruger did address the regression problem in their 1999 paper and that, in subsequent work, he has corrected for regression effects and still finds his numbers hold up.

Cross-cultural comparisons

Regardless of how pervasive the phenomenon is, it is clear from Dunning's and others' work that many Americans, at least sometimes and under some conditions, have a tendency to inflate their worth. It is interesting, therefore, to see the phenomenon's mirror opposite in another culture. In research comparing North American and East Asian self-assessments, Heine of the University of British Columbia finds that East Asians tend to underestimate their abilities, with an aim toward improving the self and getting along with others.

These differences are highlighted in a meta-analysis Heine is now completing of 70 studies that examine the degree of self-enhancement or self-criticism in China, Japan and Korea versus the United States and Canada. Sixty-nine of the 70 studies reveal significant differences between the two cultures in the degree to which individuals hold these tendencies, he finds.

In another article in the October 2001 Journal of Personality and Social Psychology (Vol. 81, No. 4), Heine's team looks more closely at how this occurs. First, Japanese and American participants performed a task at which they either succeeded or failed. Then they were timed as they worked on another version of the task. "The results made a symmetrical X," says Heine: Americans worked longer if they succeeded at the first task, while Japanese worked longer if they failed.

There are cultural, social and individual motives behind these tendencies, Heine and colleagues observe in a paper in the October 1999 Psychological Review (Vol. 106, No. 4). "As Western society becomes more individualistic, a successful life has come to be equated with having high self-esteem," Heine says. "Inflating one's sense of self creates positive emotions and feelings of self-efficacy, but the downside is that people don't really like self-enhancers very much."

Conversely, East Asians' self-improving or self-critical stance helps them maintain their "face," or reputation, and as a result, their interpersonal network. But the cost is they don't feel as good about themselves, he says. Because people in these cultures have different motivations, they make very different choices, Heine adds. If Americans perceive they're not doing well at something, they'll look for something else to do instead. "If you're bad at volleyball, well fine, you won't play volleyball," as Heine puts it. East Asians, though, view a poor performance as an invitation to try harder.

Interestingly, children in many cultures tend to overrate their abilities, perhaps because they lack objective feedback about their performance. For example, until about third grade, German youngsters generally overrate their academic achievement and class standing. This tendency declines as feedback in the form of letter grades begins. But researchers also have shown significant cross-cultural differences in youngsters' performance estimates--American children, it appears, are particularly prone to overestimate their competence. Other cross-cultural differences appear in whether children attribute good performance to ability or to effort, and in strategies used to improve performance. Researchers have linked different teaching strategies to these variations (visit www.vcld.org/pages/newsletters/01_02_fall/attribu.htm for references).

Wanted: good feedback

One antidote to inaccurate self-assessment is high-quality feedback, Dunning says. One place such feedback would be particularly useful, for instance, is in the medical arena, where physicians are mandated to identify their own weaknesses and improve on them through education and research. The difficulty is that doctors--and for that matter, people in general--often can't see those weaknesses, he says.

Dunning is now starting a study that will look more closely at the issue of "blind spots." If indeed people avoid improvement because they simply don't see their own failings, the area is ripe for intervention, he believes.

"A little pointed feedback might be the exact motivator people need to work on their shortcomings," says Dunning. "If adolescents don't realize that they really know very little about safe sex, or physicians don't know that medical technology and information has significantly changed, they can't be expected to be motivated to improve their situation."

Tori DeAngelis is a writer in Syracuse, N.Y.