When people believe a tale that conflicts with self-checkable evidence it tells me that people undervalue the role of evidence in forming an internal belief system. Why this is so is not clear but it enables many people to hold fast to ideas and notions based purely on supposition.

Neil deGrasse Tyson
Death by Black Hole: And Other Cosmic Quandaries
[This is a good book. It’s especially entertaining when he lets lose with a rant. But, back on point, I believe the reason is very clear. People believe what they want to believe. It’s rare that people will believe the evidence when it is contrary to a position they have invested in. That investment can be of any type including political and emotional, as well as financial. Belief in god(s), gun control, communism, and (redundancy alert) the Democrat party are prime examples. Chris Phillips encapsulated the appropriate conclusion and cure with much wider application than he originally suggested. Although he never discussed it with me I believe that conclusion was based on the basic truth of investing in your beliefs tends to close your thinking. See also When Prophecy Fails and Cognitive dissonance.–Joe]