First steps in analyzing stupidity

"Smart is the ability to solve hard problems, which can be done many ways. Stupid is a tendency to not comprehend easy problems." 

So writes Morgan Housel at the Collaborative Fund's blog. While the examples tend to focus on finance and economics, the lessons can be applied in many ways . . . 

For instance, one way of being stupid is "Discounting the views of people who aren’t as credentialed as you are, underestimating the special knowledge they have since they’ve experienced a world you haven’t."