Do you use flawed reasoning? This site http://www.prioritysystem.com/reasons1.html
mentions some fallacies in our thinking...

Do you....

"Base the credibility of an argument on its manner of presentation?"

"Give preferential treatment to those perceived to be group members?"

"See patterns where none exist?"

"Underestimate the time/effort to complete a difficult task?"

These are just a few of the many examples.