General Discussion

In their initial ratings, they estimated that they had solved 5.8 problems correctly. On their second ratings, they raised that estimate to 6.3, t(l 7) = 2.62, p < .02.

For individuals who scored in the top quartile, training had a very different effect. As we did for their bottom-quartile counterparts, we conducted a set of 2 (training: yes or no) X 2 (pre- vs. postmanipulation) ANOV As. These analyses revealed significant interactions for estimates of test performance, F(l, 26) = 6.39, p < .025, and raw score, F(l, 26) = 4.95, p < .05, but not for estimates of general ability, F(l, 26) = 1.03, ns.

As Table 2 illustrates, top-quartile participants in the training condition thought their score fell in the 78th percentile prior to receiving the training materials. Afterward, they increased that estimate to the 87th percentile, t(12) = 2.66, p < .025. Topquartile participants also raised their estimates of their percentile ability, t(l2) = 1.91,p < .09, and raw test score, t(12) = 2.99,p < .025, although only the latter difference was significant. In contrast, top-quartile participants in the control condition did not revise their estimates on any of these measures, ts < 1. Although not predicted, these revisions are perhaps not surprising in light of the fact that top-quartile participants in the training condition received validation that the logical reasoning they had used was perfect! y correct.

The mediational role of metacognitive skills. We have argued that less competent individuals overestimate their abilities because they lack the metacog_qitive skills to recognize the error of their own decisions. In other words, we believe that deficits in metacognitive skills mediate the link between low objective performance and inflated ability assessment. The next two analyses were designed to test this mediational relationship more explicitly.

In the first analysis, we examined objective performance, metacognitive skill, and the accuracy of self-appraisals in a manner suggested by Baron and Kenny (1986). According to their procedure, metacognitive skill would be shown to mediate the link between incompetence and inflated self-assessment if (a) low levels of objective performance were associated with inflated self-assessment, (b) low levels of objective performance were associated with deficits in metacognitive skill, and ( c) deficits in metacognitive skill were associated with inflated self-assessment even after controlling for objective performance.

Focusing on the 70 participants in the untrained group, we found considerable evidence of mediation. First, as reported earlier, participants’ test performance was a strong predictor of how much they overestimated their ability and test performance. An additional analysis revealed that test performance was also strongly related to metacognitive skill, {3(68) = .75, p < .0001. Finally, and most important, deficits in metacognitive skill predicted inflated selfassessment on the all three self-ratings we examined (general logical reasoning ability, comparative performance on the test, and absolute score on the test)-even after objective performance on the test was held constant. This was true for the first set of self-appraisals, f3s(67) = -.40 to -.49, ps < .001, as well as the second, f3s(67) = -.41 to - .50, ps < .001.5

Given these results, one could wonder whether the impact of training on the self-assessments of participants in the bottom quartile was similarly mediated by metacognitive skills. To find out, we conducted a mediational analysis focusing on bottom quartile participants in both trained and untrained groups. Here too, all three mediational links were supported. As previously reported, bottom-quartile participants who received training (a) provided less inflated self-assessments and (b) evidenced better metacognitive skills than those who did not receive training. Completing this analysis, regression analyses revealed that metacognitive skills predicted inflated self-assessment with participants’ training condition held constant, f3(34)s = - .68 to - .97, ps < .01. In fact, training itself failed to predict miscalibration when bottomquartile participants’ metacognitive skills were taken into account, f3s(34) = .00 to .25, ns. These analyses suggest that the benefit of training on the accuracy of self-assessment was achieved by means of improved metacognitive skills. 6

Summary

Thomas Jefferson once said, “he who knows best best knows how little he knows.” In Study 4, we obtained experimental support for this assertion. Participants scoring in the bottom quartile on a test of logic grossly overestimated their test performance-but became significantly more calibrated after their logical reasoning skills were improved. In contrast, those in the bottom quartile who did not receive this aid continued to hold the mistaken impression that they had performed just fine. Moreover, mediational analyses revealed that it was by means of their improved metacognitive skills that incompetent individuals arrived at their more accurate self-appraisals.

General Discussion

In the neurosciences, practitioners and researchers occasionally come across the curious malady of anosognosia. Caused by certain types of damage to the right side of the brain, anosognosia leaves people paralyzed on the left side of their body. But more than that, when doctors place a cup in front of such patients and ask them to pick it up with their left hand, patients not only fail to comply but also fail to understand why. When asked to explain their failure, such patients might state that they are tired, that they did not hear the doctor’s instructions, or that they did not feel like respondingbut never that they are suffering from paralysis. In essence, anosognosia not only causes paralysis, but also the inability to realize that one is paralyzed (D’ Amasio, 1994).

In this article, we proposed a psychological analogue to anosognosia. We argued that incompetence, like anosognosia, not only causes poor performance but also the inability to recognize that one’s performance is poor. Indeed, across the four studies, participants in the bottom quartile not only overestimated themselves, but thought they were above-average, Z = 4.64, p < .0001. In a phrase, Thomas Gray was right: Ignorance is bliss-at least when it comes to assessments of one’s own ability.

What causes this gross overestimation?

Studies 3 and 4 pointed to a lack of metacognitive skills among less skilled participants.

Bottom-quartile participants were less successful than were topquartile participants in the metacognitive tasks of discerning what one has answered correctly versus incorrectly (Study 4) and distinguishing superior from inferior performances on the part of one’s peers (Study 3).

More conclusively, Study 4 showed that improving participants’ metacognitive skills also improved the accuracy of their self-appraisals.

Note that these findings are inconsistent with a simple regression effect interpretation of our results, which does not predict any changes in self-appraisals given different levels of metacognitive skill. Regression also cannot explain the fact that bottom-quartile participants were nearly 4 times more miscalibrated than their top-quartile counterparts.

Study 4 also revealed a paradox. It suggested that one way to make people recognize their incompetence is to make them competent. Once we taught bottom-quartile participants how to solve Wason selection tasks correctly, they also gained the metacognitive skills to recognize the previous error of their ways.

Of course, and herein lies the paradox, once they gained the metacognitive skills to recognize their own incompetence, they were no longer incompetent. “To have such knowledge,” as Miller (1993) put it in the quote that began this article, “would already be to remedy a good portion of the offense.”

The Burden of Expertise

Although our emphasis has been on the miscalibration of incompetent individuals, along the way we discovered that highly competent individuals also show some systematic bias in their self appraisals. Across the four sets of studies, participants in the top quartile tended to underestimate their ability and test performance relative to their peers, Zs = -5.66 and -4.77, respectively, ps < .0001. What accounts for this underestimation? Here, too, the regression effect seems a likely candidate: Just as extremely low performances are likely to be associated with slightly higher perceptions of performance, so too are extremely high performances likely to be associated with slightly lower perceptions of performance.

As it turns out, however, our data point to a more psychological explanation. Specifically, top-quartile participants appear to have fallen prey to a false-consensus effect (Ross et al., 1977). Simply put, these participants assumed that because they performed so well, their peers must have performed well likewise.

This would have led top-quartile participants to underestimate their comparative abilities (i.e., how their general ability and test performance compare with that of their peers), but not their absolute abilities (i.e., their raw score on the test).

This was precisely the pattern of data we observed: Compared with participants falling in the third quartile, participants in the top quartile were an average of 23% less calibrated in terms of their comparative performance on the test-but 16% more calibrated in terms of their objective performance on the test.7

More conclusive evidence came from Phase 2 of Study 3. Once top-quartile participants learned how poorly their peers had performed, they raised their self-appraisals to more accurate levels. We have argued that unskilled individuals suffer a dual burden: Not only do they perform poorly, but they fail to realize it. It thus appears that extremely competent individuals suffer a burden as well. Although they perform competently, they fail to realize that their proficiency is not necessarily shared by their peers.