If a man is offered a fact which goes against his instincts, he will scrutinize it closely, and unless the evidence is overwhelming, he will refuse to believe it. If, on the other hand, he is offered something which affords a reason for acting in accordance to his instincts, he will accept it even on the slightest evidence. The origin of myths is explained in this way. –Bertrand Russell
I largely agree with the quote above, but I have to amend it a little. Humans have an amazing ability to rationalize their prejudices and preferences, to the point where they will refuse to believe something despite a mountain of evidence, or fervently believe something not only in the complete absence of evidence, but in the presence of a mountain of contradictory evidence. (That’s why so many religions make unquestioning faith the highest of virtues, especially when that faith contradicts “worldly” knowledge. That’s how Tertullian could proudly proclaim “I believe because it is impossible.”) To modify yet another famous quote, I’d say there are only two things that are infinite: the universe, and the human capacity for self-deception…and I’m not so sure about the former.
Case in point: the Casey Anthony case, and the brand new “Craigslist Killer” case.
The friends and relatives of the man arrested in connection with a slaying and several robberies of women advertising services on Craigslist are in denial about the situation, because the admission that their friend/fiancee is a robber and murderer would upset some of their core beliefs about themselves: that they are good people, and that they are good enough judges of character to not hang out with (or be engaged to) bad people. His fiancee sent an angry email to ABC News, insisting that the whole thing is just “cops trying to make money off accusing an innocent man.”
“Unfortunately you were given wrong information as was the public,” Megan McAllister wrote to ABC News in an e-mail. “All I have to say to you is Philip is a beautiful person inside and out and could not hurt a fly! A police officer in Boston (or many) is trying to make big bucks by selling this false story to the TV stations. What else is new?? Philip is an intelligent man who is just trying to live his life so if you could leave us alone we would greatly appreciate it. We expect to marry in August and share and wonderful, meaningful life together.”
In the Casey Anthony case, her parents still insist that she is innocent and a victim of malicious prosecution, despite all the evidence to the contrary. When they were in court to respond to a civil lawsuit recently, they lashed out at the lawyers and reporters, claiming all these people had destroyed the Anthony family and ruined their lives. When they left the deposition, Casey’s mother shouted, “You have to have faith! If you don’t have faith, you don’t have hope!”
That, of course, cuts right to the heart of the matter. When people are faced with accepting a reality that is just too fundamentally threatening to their most dearly held beliefs, they have a vested interest in denying that reality just for reasons of mental self-preservation. They will deny the evidence for that reality, and latch on to anything that will enable them to continue their self-deception. It’s a natural–and very effective–defense mechanism. The alternative would be to admit that you are indeed capable of making friends with (or getting engaged to) a murderer…that your daughter did indeed kill your granddaughter…or that demographics and geography have far more to do with your chosen religious affiliation than its inherent truth does.
The trouble is that humans are wired for seeking out truth, and that even the most elaborate act of self-deception can’t ever suppress the knowledge that it is, indeed, self-deception. That knowledge sits in some corner of the brain, and its presence causes discomfort through cognitive dissonance for as long as its bearer refuses to match their world view with the facts.