Barack Obama

The Dunning–Kruger effect is a cognitive bias in which unskilled individuals suffer from illusory superiority, mistakenly rating their ability much higher than average. This bias is attributed to a metacognitive inability of the unskilled to recognize their mistakes.[1]

Actual competence may weaken self-confidence, as competent individuals may falsely assume that others have an equivalent understanding. David Dunning and Justin Kruger of Cornell University conclude, "the miscalibration of the incompetent stems from an error about the self, whereas the miscalibration of the highly competent stems from an error about others".[2]

http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect

I've found it to be true, as the most intelligent people I know are usually humble and open to listening, realizing there is so much to learn, that they cannot know it all.

Those who are arrogant and dismissive of seeking unpopular possibilities I have found on the other end of the scale, and are qutie sure of themselves. They have no reason to change their views, as they cannot maintain the neutral mental state to process information that might send them to find out more. They don't have respect for data or factual content, they decide quickly based on little knowledge what happens in front of them.

This can also be created by stress, narrowing the focus of awareness and causing the person to repeat the actions of others without thinking. I never discount it dealing with others. I know a stampede when I see one.