* Incompetent individuals tend to overestimate their own level of skill.
* Incompetent individuals fail to recognize genuine skill in others.
* Incompetent individuals fail to recognize the extremity of their inadequacy.
They found, for instance, that "individuals who scored in the 12th percentile believed that their general reasoning abilities fell at the 68th percentile". Curiously, even the top students "tended to overestimate" the incompetent ones. But at least they were better at assessing themselves. (I wouldn't be surprised if there was actually a reverse effect at higher levels -- cf. Colin Marshall's 'Why Smart People Often Think They're The Dumbest Person in the Room').
Should such research lead us to place less weight on subjective (self-)assessment, and more on external indicators of success?