Unskilled and Unaware of It : How Difficulties in Recognizing One's Own Incompetence Lead to Inflated Self-Assessments

Unskilled and Unaware of It: How Difficulties in Recognizing One’s Ow...
http://www.apa.org/journals/psp/psp7761121.html
Journal of


Personality and

Social Psychology

Selected Article
© 1999 by the American Psychological Association

For personal use only--not for distribution
December 1999 Vol. 77, No. 6, 1121-1134

Unskilled and Unaware of It: How
Difficulties in Recognizing One’s Own
Incompetence Lead to Inflated
Self-Assessments
Justin Kruger and David Dunning
Department of Psychology
Cornell University

Abstract
People tend to hold overly favorable views of their
abilities in many social and intellectual domains. The
authors suggest that this overestimation occurs, in
part, because people who are unskilled in these
domains suffer a dual burden: Not only do these
people reach erroneous conclusions and make
unfortunate choices, but their incompetence robs them
of the metacognitive ability to realize it. Across 4
studies, the authors found that participants scoring in
the bottom quartile on tests of humor, grammar, and
logic grossly overestimated their test performance and
ability. Although their test scores put them in the 12th
percentile, they estimated themselves to be in the
62nd. Several analyses linked this miscalibration to
deficits in metacognitive skill, or the capacity to
distinguish accuracy from error. Paradoxically,
improving the skills of participants, and thus
increasing their metacognitive competence, helped
them recognize the limitations of their abilities.
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We thank Betsy Ostrov, Mark Stalnaker, and Boris Veysman for their assistance in
data collection. We also thank Andrew Hayes, Chip Heath, Rich Gonzalez, Ken
Savitsky, and David Sherman for their valuable comments on an earlier version of
this article, and Dov Cohen for alerting us to the quote we used to begin this article.
Portions of this research were presented at the annual meeting of the Eastern
Psychological Association, Boston, March 1998. This research was supported
financially by National Institute of Mental Health Grant RO1 56072.
Correspondence concerning this article should be addressed to Justin Kruger,
Department of Psychology, University of Illinois at Urbana- Champaign, 603 East
Daniel Street, Champaign, Illinois 61820, or to David Dunning, Department of
Psychology, Uris Hall, Cornell University, Ithaca, New York 14853-7601. Electronic
mail may be sent to jkruger@ s.psych.uiuc.edu or to dad6@cornell.edu.
Received January 25, 1999; revision received May 28, 1999; accepted June 10, 1999
It is one of the essential features of such incompetence
that the person so afflicted is incapable of knowing
that he is incompetent. To have such knowledge
would already be to remedy a good portion of the
offense. ( Miller, 1993 , p. 4)
In 1995, McArthur Wheeler walked into two Pittsburgh banks and
robbed them in broad daylight, with no visible attempt at disguise.
He was arrested later that night, less than an hour after videotapes
of him taken from surveillance cameras were broadcast on the 11
o’clock news. When police later showed him the surveillance
tapes, Mr. Wheeler stared in incredulity. "But I wore the juice," he
mumbled. Apparently, Mr. Wheeler was under the impression that
rubbing one’s face with lemon juice rendered it invisible to
videotape cameras ( Fuocco, 1996 ).
We bring up the unfortunate affairs of Mr. Wheeler to make three
points. The first two are noncontroversial. First, in many domains
in life, success and satisfaction depend on knowledge, wisdom, or
savvy in knowing which rules to follow and which strategies to
pursue. This is true not only for committing crimes, but also for
many tasks in the social and intellectual domains, such as
promoting effective leadership, raising children, constructing a
solid logical argument, or designing a rigorous psychological
study. Second, people differ widely in the knowledge and
strategies they apply in these domains ( Dunning, Meyerowitz, &
Holzberg, 1989 ; Dunning, Perie, & Story, 1991 ; Story &
Dunning, 1998 ), with varying levels of success. Some of the
knowledge and theories that people apply to their actions are
sound and meet with favorable results. Others, like the lemon juice
hypothesis of McArthur Wheeler, are imperfect at best and
wrong-headed, incompetent, or dysfunctional at worst.
Perhaps more controversial is the third point, the one that is the
focus of this article. We argue that when people are incompetent in
the strategies they adopt to achieve success and satisfaction, they
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suffer a dual burden: Not only do they reach erroneous
conclusions and make unfortunate choices, but their incompetence
robs them of the ability to realize it. Instead, like Mr. Wheeler,
they are left with the mistaken impression that they are doing just
fine. As Miller (1993) perceptively observed in the quote that
opens this article, and as Charles Darwin (1871) sagely noted over
a century ago, "ignorance more frequently begets confidence than
does knowledge" (p. 3).
In essence, we argue that the skills that engender competence in a
particular domain are often the very same skills necessary to
evaluate competence in that domain–one’s own or anyone else’s.
Because of this, incompetent individuals lack what cognitive
psychologists variously term metacognition ( Everson & Tobias,
1998 ), metamemory ( Klin, Guizman, & Levine, 1997 ),
metacomprehension ( Maki, Jonas, & Kallod, 1994 ), or
self-monitoring skills ( Chi, Glaser, & Rees, 1982 ). These terms
refer to the ability to know how well one is performing, when one
is likely to be accurate in judgment, and when one is likely to be in
error. For example, consider the ability to write grammatical
English. The skills that enable one to construct a grammatical
sentence are the same skills necessary to recognize a grammatical
sentence, and thus are the same skills necessary to determine if a
grammatical mistake has been made. In short, the same knowledge
that underlies the ability to produce correct judgment is also the
knowledge that underlies the ability to recognize correct judgment.
To lack the former is to be deficient in the latter.
Imperfect Self-Assessments
We focus on the metacognitive skills of the incompetent to
explain, in part, the fact that people seem to be so imperfect in
appraising themselves and their abilities. 1 Perhaps the best
illustration of this tendency is the "above-average effect," or the
tendency of the average person to believe he or she is above
average, a result that defies the logic of descriptive statistics (
Alicke, 1985 ; Alicke, Klotz, Breitenbecher, Yurak, &
Vredenburg, 1995 ; Brown & Gallagher, 1992 ; Cross, 1977 ;
Dunning et al., 1989 ; Klar, Medding, & Sarel, 1996 ; Weinstein,
1980 ; Weinstein & Lachendro, 1982 ). For example, high school
students tend to see themselves as having more ability in
leadership, getting along with others, and written expression than
their peers ( College Board, 1976—1977 ), business managers
view themselves as more able than the typical manager ( Larwood
& Whittaker, 1977 ), and football players see themselves as more
savvy in "football sense" than their teammates ( Felson, 1981 ).
We believe focusing on the metacognitive deficits of the unskilled
may help explain this overall tendency toward inflated
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self-appraisals. Because people usually choose what they think is
the most reasonable and optimal option ( Metcalfe, 1998 ), the
failure to recognize that one has performed poorly will instead
leave one to assume that one has performed well. As a result, the
incompetent will tend to grossly overestimate their skills and
abilities.
Competence and Metacognitive Skills
Several lines of research are consistent with the notion that
incompetent individuals lack the metacognitive skills necessary for
accurate self- assessment. Work on the nature of expertise, for
instance, has revealed that novices possess poorer metacognitive
skills than do experts. In physics, novices are less accurate than
experts in judging the difficulty of physics problems ( Chi et al.,
1982 ). In chess, novices are less calibrated than experts about how
many times they need to see a given chessboard position before
they are able to reproduce it correctly ( Chi, 1978 ). In tennis,
novices are less likely than experts to successfully gauge whether
specific play attempts were successful ( McPherson & Thomas,
1989 ).
These findings suggest that unaccomplished individuals do not
possess the degree of metacognitive skills necessary for accurate
self-assessment that their more accomplished counterparts possess.
However, none of this research has examined whether
metacognitive deficiencies translate into inflated self-assessments
or whether the relatively incompetent (novices) are systematically
more miscalibrated about their ability than are the competent
(experts).
If one skims through the psychological literature, one will find
some evidence that the incompetent are less able than their more
skilled peers to gauge their own level of competence. For example,
Fagot and O’Brien (1994) found that socially incompetent boys
were largely unaware of their lack of social graces (see Bem &
Lord, 1979 , for a similar result involving college students).
Mediocre students are less accurate than other students at
evaluating their course performance ( Moreland, Miller, & Laucka,
1981 ). Unskilled readers are less able to assess their text
comprehension than are more skilled readers ( Maki, Jonas, &
Kallod, 1994 ). Students doing poorly on tests less accurately
predict which questions they will get right than do students doing
well ( Shaughnessy, 1979 ; Sinkavich, 1995 ). Drivers involved in
accidents or flunking a driving exam predict their performance on
a reaction test less accurately than do more accomplished and
experienced drivers ( Kunkel, 1971 ). However, none of these
studies has examined whether deficient metacognitive skills
underlie these miscalibrations, nor have they tied these
miscalibrations to the above-average effect.
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Predictions
These shards of empirical evidence suggest that incompetent
individuals have more difficulty recognizing their true level of
ability than do more competent individuals and that a lack of
metacognitive skills may underlie this deficiency. Thus, we made
four specific predictions about the links between competence,
metacognitive ability, and inflated self-assessment.
Prediction 1. Incompetent individuals, compared with their more
competent peers, will dramatically overestimate their ability and
performance relative to objective criteria.
Prediction 2. Incompetent individuals will suffer from deficient
metacognitive skills, in that they will be less able than their more
competent peers to recognize competence when they see it–be it
their own or anyone else’s.
Prediction 3. Incompetent individuals will be less able than their
more competent peers to gain insight into their true level of
performance by means of social comparison information. In
particular, because of their difficulty recognizing competence in
others, incompetent individuals will be unable to use information
about the choices and performances of others to form more
accurate impressions of their own ability.
Prediction 4. The incompetent can gain insight about their
shortcomings, but this comes (paradoxically) by making them
more competent, thus providing them the metacognitive skills
necessary to be able to realize that they have performed poorly.
The Studies
We explored these predictions in four studies. In each, we
presented participants with tests that assessed their ability in a
domain in which knowledge, wisdom, or savvy was crucial: humor
(Study 1), logical reasoning (Studies 2 and 4), and English
grammar (Study 3). We then asked participants to assess their
ability and test performance. In all studies, we predicted that
participants in general would overestimate their ability and
performance relative to objective criteria. But more to the point,
we predicted that those who proved to be incompetent (i.e., those
who scored in the bottom quarter of the distribution) would be
unaware that they had performed poorly. For example, their score
would fall in the 10th or 15th percentile among their peers, but
they would estimate that it fell much higher (Prediction 1). Of
course, this overestimation could be taken as a mathematical
verity. If one has a low score, one has a better chance of
overestimating one’s performance than underestimating it. Thus,
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the real question in these studies is how much those who scored
poorly would be miscalibrated with respect to their performance.
In addition, we wanted to examine the relationship between
miscalibrated views of ability and metacognitive skills, which we
operationalized as (a) the ability to distinguish what one has
answered correctly from what one has answered incorrectly and
(b) the ability to recognize competence in others. Thus, in Study 4,
we asked participants to not only estimate their overall
performance and ability, but to indicate which specific test items
they believed they had answered correctly and which incorrectly.
In Study 3, we showed competent and incompetent individuals the
responses of others and assessed how well participants from each
group could spot good and poor performances. In both studies, we
predicted that the incompetent would manifest poorer
metacognitive skills than would their more competent peers
(Prediction 2).
We also wanted to find out what experiences or interventions
would make low performers realize the true level of performance
that they had attained. Thus, in Study 3, we asked participants to
reassess their own ability after they had seen the responses of their
peers. We predicted that competent individuals would learn from
observing the responses of others, thereby becoming better
calibrated about the quality of their performance relative to their
peers. Incompetent participants, in contrast, would not (Prediction
3). In Study 4, we gave participants training in the domain of
logical reasoning and explored whether this newfound competence
would prompt incompetent individuals toward a better
understanding of the true level of their ability and test performance
(Prediction 4).
Study 1: Humor
In Study 1, we decided to explore people’s perceptions of their
competence in a domain that requires sophisticated knowledge and
wisdom about the tastes and reactions of other people. That
domain was humor. To anticipate what is and what others will find
funny, one must have subtle and tacit knowledge about other
people’s tastes. Thus, in Study 1 we presented participants with a
series of jokes and asked them to rate the humor of each one. We
then compared their ratings with those provided by a panel of
experts, namely, professional comedians who make their living by
recognizing what is funny and reporting it to their audiences. By
comparing each participant’s ratings with those of our expert
panel, we could roughly assess participants’ ability to spot humor.
Our key interest was how perceptions of that ability converged
with actual ability. Specifically, we wanted to discover whether
those who did poorly on our measure would recognize the low
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quality of their performance. Would they recognize it or would
they be unaware?
Method
Participants. Participants were 65 Cornell University
undergraduates from a variety of courses in psychology who
earned extra credit for their participation.
Materials. We created a 30-item questionnaire made up of jokes
we felt were of varying comedic value. Jokes were taken from
Woody Allen (1975) , Al Frankin (1992) , and a book of "really
silly" pet jokes by Jeff Rovin (1996) . To assess joke quality, we
contacted several professional comedians via electronic mail and
asked them to rate each joke on a scale ranging from 1 ( not at all
funny ) to 11 ( very funny ). Eight comedians responded to our
request (Bob Crawford, Costaki Economopoulos, Paul Frisbie,
Kathleen Madigan, Ann Rose, Allan Sitterson, David Spark, and
Dan St. Paul). Although the ratings provided by the eight
comedians were moderately reliable ( = .72), an analysis of
interrater correlations found that one (and only one) comedian’s
ratings failed to correlate positively with the others (mean r =
.09). We thus excluded this comedian’s ratings in our calculation
of the humor value of each joke, yielding a final of .76. Expert
ratings revealed that jokes ranged from the not so funny (e.g.,
"Question: What is big as a man, but weighs nothing? Answer: His
shadow." Mean expert rating = 1.3) to the very funny (e.g., "If a
kid asks where rain comes from, I think a cute thing to tell him is
’God is crying.’ And if he asks why God is crying, another cute
thing to tell him is ’probably because of something you did.’"
Mean expert rating = 9.6).
Procedure. Participants rated each joke on the same 11-point scale
used by the comedians. Afterward, participants compared their
"ability to recognize what’s funny" with that of the average
Cornell student by providing a percentile ranking. In this and in all
subsequent studies, we explained that percentile rankings could
range from 0 ( I’m at the very bottom ) to 50 ( I’m exactly average
) to 99 ( I’m at the very top ).
Results and Discussion
Gender failed to qualify any results in this or any of the studies
reported in this article, and thus receives no further mention.
Our first prediction was that participants overall would
overestimate their ability to tell what is funny relative to their
peers. To find out whether this was the case, we first assigned each
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participant a percentile rank based on the extent to which his or
her joke ratings correlated with the ratings provided by our panel
of professionals (with higher correlations corresponding to better
performance). On average, participants put their ability to
recognize what is funny in the 66th percentile, which exceeded the
actual mean percentile (50, by definition) by 16 percentile points,
one-sample t (64) = 7.02, p < .0001. This overestimation occurred
even though self-ratings of ability were significantly correlated
with our measure of actual ability, r (63) = .39, p < .001.
Our main focus, however, is on the perceptions of relatively
"incompetent" participants, which we defined as those whose test
score fell in the bottom quartile ( n = 16). As Figure 1 depicts,
these participants grossly overestimated their ability relative to
their peers. Whereas their actual performance fell in the 12th
percentile, they put themselves in the 58th percentile. These
estimates were not only higher than the ranking they actually
achieved, paired t (15) = 10.33, p < .0001, but were also
marginally higher than a ranking of "average" (i.e., the 50th
percentile), one-sample t (15) = 1.96, p < .07. That is, even
participants in the bottom quarter of the distribution tended to feel
that they were better than average.
As Figure 1 illustrates, participants in other quartiles did not
overestimate their ability to the same degree. Indeed, those in the
top quartile actually underestimated their ability relative to their
peers, paired t (15) = 2.20, p < .05.
Summary
In short, Study 1 revealed two effects of interest. First, although
perceptions of ability were modestly correlated with actual ability,
people tended to overestimate their ability relative to their peers.
Second, and most important, those who performed particularly
poorly relative to their peers were utterly unaware of this fact.
Participants scoring in the bottom quartile on our humor test not
only overestimated their percentile ranking, but they overestimated
it by 46 percentile points. To be sure, they had an inkling that they
were not as talented in this domain as were participants in the top
quartile, as evidenced by the significant correlation between
perceived and actual ability. However, that suspicion failed to
anticipate the magnitude of their shortcomings.
At first blush, the reader may point to the regression effect as an
alternative interpretation of our results. After all, we examined the
perceptions of people who had scored extremely poorly on the
objective test we handed them, and found that their perceptions
were less extreme than their reality. Because perceptions of ability
are imperfectly correlated with actual ability, the regression effect
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virtually guarantees this result. Moreover, because incompetent
participants scored close to the bottom of the distribution, it was
nearly impossible for them to underestimate their performance.
Despite the inevitability of the regression effect, we believe that
the overestimation we observed was more psychological than
artifactual. For one, if regression alone were to blame for our
results, then the magnitude of miscalibration among the bottom
quartile would be comparable with that of the top quartile. A
glance at Figure 1 quickly disabuses one of this notion. Still, we
believe this issue warrants empirical attention, which we devote in
Studies 3 and 4.
Study 2: Logical Reasoning
We conducted Study 2 with three goals in mind. First, we wanted
to replicate the results of Study 1 in a different domain, one
focusing on intellectual rather than social abilities. We chose
logical reasoning, a skill central to the academic careers of the
participants we tested and a skill that is called on frequently. We
wondered if those who do poorly relative to their peers on a
logical reasoning test would be unaware of their poor
performance.
Examining logical reasoning also enabled us to compare perceived
and actual ability in a domain less ambiguous than the one we
examined in the previous study. It could reasonably be argued that
humor, like beauty, is in the eye of the beholder. 2 Indeed, the
imperfect interrater reliability among our group of professional
comedians suggests that there is considerable variability in what is
considered funny even by experts. This criterion problem, or lack
of uncontroversial criteria against which self-perceptions can be
compared, is particularly problematic in light of the tendency to
define ambiguous traits and abilities in ways that emphasize one’s
own strengths ( Dunning et al., 1989 ). Thus, it may have been the
tendency to define humor idiosyncratically, and in ways favorable
to one’s tastes and sensibilities, that produced the miscalibration
we observed–not the tendency of the incompetent to miss their
own failings. By examining logical reasoning skills, we could
circumvent this problem by presenting students with questions for
which there is a definitive right answer.
Finally, we wanted to introduce another objective criterion with
which we could compare participants’ perceptions. Because
percentile ranking is by definition a comparative measure, the
miscalibration we saw could have come from either of two
sources. In the comparison, participants may have overestimated
their own ability (our contention) or may have underestimated the
skills of their peers. To address this issue, in Study 2 we added a
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second criterion with which to compare participants’ perceptions.
At the end of the test, we asked participants to estimate how many
of the questions they had gotten right and compared their estimates
with their actual test scores. This enabled us to directly examine
whether the incompetent are, indeed, miscalibrated with respect to
their own ability and performance.
Method
Participants. Participants were 45 Cornell University
undergraduates from a single introductory psychology course who
earned extra credit for their participation. Data from one additional
participant was excluded because she failed to complete the
dependent measures.
Procedure. Upon arriving at the laboratory, participants were told
that the study focused on logical reasoning skills. Participants then
completed a 20-item logical reasoning test that we created using
questions taken from a Law School Admissions Test (LSAT) test
preparation guide ( Orton, 1993 ). Afterward, participants made
three estimates about their ability and test performance. First, they
compared their "general logical reasoning ability" with that of
other students from their psychology class by providing their
percentile ranking. Second, they estimated how their score on the
test would compare with that of their classmates, again on a
percentile scale. Finally, they estimated how many test questions
(out of 20) they thought they had answered correctly. The order in
which these questions were asked was counterbalanced in this and
in all subsequent studies.
Results and Discussion
The order in which specific questions were asked did not affect
any of the results in this or in any of the studies reported in this
article and thus receives no further mention.
As expected, participants overestimated their logical reasoning
ability relative to their peers. On average, participants placed
themselves in the 66th percentile among students from their class,
which was significantly higher than the actual mean of 50,
one-sample t (44) = 8.13, p < .0001. Participants also
overestimated their percentile rank on the test, M percentile = 61,
one-sample t (44) = 4.70, p < .0001. Participants did not, however,
overestimate how many questions they answered correctly, M =
13.3 (perceived) vs. 12.9 (actual), t < 1. As in Study 1, perceptions
of ability were positively related to actual ability, although in this
case, not to a significant degree. The correlations between actual
ability and the three perceived ability and performance measures
ranged from .05 to .19, all ns.
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