The article is persuasive in showing that people tend overestimate their own skill level. For example, people who have very poor social and intellectual skills

The article is persuasive in showing that people tend overestimate their own skill level. For example, people who have very poor social and intellectual skills (below 25th percentile ) still seem to think they are "above average" (roughly 62nd percentile). However, it is also very clear from their graphs that, overall, people simply seem to map the normal range of abilities (0% to 100%) into the compressed range (50% to 100%). I wonder if this has anything to do with how we grade in school, ... namely, anything below 50% is a "failure".