Via a comment on Pharyngula, "Inept individuals ooze confidence, study finds":
There are many incompetent people in the world. Dr. David Dunning is haunted by the fear he might be one of them.
A study conducted at Cornell University found that incompetent people are less able to judge competence and consequently don’t consider themselves to be incompetent. It’s an intuitive result. Everyone rates themselves highly at some task, some because they’re good, some because they’re so bad they can’t even tell. Interestingly it seems that the most competent people in the tests performed were likely to under-rate themselves but corrected their ratings when shown the results that others attained.
Unlike their unskilled counterparts, the most able subjects in the study were likely to underestimate their own competence […] When high scoring subjects were asked to "grade" the grammar tests of their peers, however, they quickly revised their evaluations of their own performance.
So now we all have to face the possibility that we’re not actually all that special, we’re just spectacularly blind to our own inadequacies. You have to ask yourself one question: Do I feel competent? Well, do you, punk?