Somewhat tangentially but still related, fanf pointed out this article (http://www.apa.org/journals/features/psp7761121.pdf) (pdf) on twitter, which argues that incompetent people are less aware of their own incompetence than capable people.

That is to say, fanf used Twitter to link to it - the article itself is considerably more than 140 characters.

I was reminded of it on bofhnet and realised I had never saved the link. A classic paper.