"people tend to hold overly favorable views of their abilities in many social and intellectual domains. the authors suggest that this overestimation occurs, in part, because people who are unskilled in these domains suffer a dual burden: not only do these people reach erroneous conclusions and make unfortunate choices, but their incompetence robs them of the metacognitive ability to realize it. (…)"
[ justin kruger and david dunning, department of psychology, cornell university: "unskilled and unaware of it: how difficulties in recognizing one's own incompetence lead to inflated self-assessments" ]