A program on National Public Radio on September 8, 2010, http://www.hereandnow.org/2010/09/rundown-98-2/,
gives us an insight into our thought processes as humans. When would we change our minds to correspond with irrefutable information or facts that support another position? As easy as it sounds, we human beings do not necessarily do that; rather we like to hold on, perhaps even more firmly, to our beliefs despite evidence to the contrary.
Check out this Boston Globe article, How Facts Backfire. If you really want to spend time with a study conducted by Brendan Nyhan at the University of Michigan about five years ago, feel free to read, When Corrections Fail: The Persistence Of Political Misperceptions (PDF).