There was a hilarious article in the papers a while back along these
lines, and I've been meaning to share it for a while.  It was reported
in an article in "Journal of Personality and Social Psychology".
Edited down, it reads:

  "American psychologists have discovered that incompetent people have
no idea how inept they are.  They have found that people who can do
things well underrate their abilities whereas the truly incompetent
remain in blissful ignorance.  The incompetent reach erroneous
conclusions and make unfortunate choices, and their incompetence robs
them of the ability to realise it.

  "The study found that those who scored in the bottom quarter of tests
of logic, grammar and humour were also those most likely to grossly
overestimate how well they had done.  When asked to evaluate their
performance, those who scored in the bottom eighth placed themselves
in the top third.  Those who really were in the top third tended to
underestimate themselves.

  "When shown other people's work, the competent tended to correct
their self-evaluation, but the incompetent did not.  Some even inflated
their self-estimates!"

I guess in our hobby we've all come across those whose work is terrible
but proclaim how good they are, and the more their mistakes are pointed
out, the higher their self-opinion gets.  It's a warning to us all!

Julian Dyer