Some excerpts from a very interesting article in the NY Times:

Most incompetent people do not know that they are incompetent.  On the contrary. People who do things badly are usually supremely confident of their abilities — more confident, in fact, than people who do things well.

One reason that the ignorant also tend to be the blissfully self-assured, the researchers believe, is that the skills required for competence often are the same skills necessary to recognize competence.

This deficiency in “self-monitoring skills” helps explain the tendency of the humor-impaired to persist in telling jokes that are not funny, of day traders to repeatedly jump into the market — and repeatedly lose out — and of the politically clueless to continue holding forth at dinner parties on the fine points of campaign strategy.

The most able subjects in the study were likely to underestimate their own competence. The researchers attributed this to the fact that, in the absence of information about how others were doing, highly competent subjects assumed that others were performing as well as they were.

When high scoring subjects were asked to “grade” the grammar tests of their peers, however, they quickly revised their evaluations of their own performance. In contrast, the self-assessments of those who scored badly themselves were unaffected by the experience of grading others; some subjects even further inflated their estimates of their own abilities.

Click here to read the entire article.