http://en.wikipedia.org/wiki/Dunning–Kruger_effectThe Dunning–Kruger effect is a cognitive bias in which unskilled individuals suffer from illusory superiority, mistakenly rating their ability much higher than average.
Basically, people with low levels of skill don't realize what actually makes someone skillful, and thus tend to significantly over-rate their own level of competence.
However, those who have high levels of skill will still figure they have highish levels of skill, but will underestimate themselves overall.Dunning and Kruger proposed that, for a given skill, incompetent people will:
- tend to overestimate their own level of skill;
- fail to recognize genuine skill in others;
- fail to recognize the extremity of their inadequacy;
- recognize and acknowledge their own previous lack of skill, if they are exposed to training for that skill.
I don't think everyone who is arrogant is simply putting on a show. I think real self-knowledge can put you in a position of understanding that you really do know what is best in a situation and thus should take authority where others are going to botch things up. It's not always clear when the situations are, but in general, if you have previous experience and proven aptitude that means a great deal.