I often find articles about religion and the paranormal written by skeptics to be really irritating. But I actually found a very good one for a change, called Why Beliefs Don’t Die (on the Committee for the Scientific Investigation of Claims of the Paranormal site).

The article talks about why it’s so difficult for people to change their beliefs, even in the face of legitimate evidence which contradicts their beliefs. Basically, the theory espoused by the author is that the main function of the brain is survival. Sensory input is the main source of information for survival. But sensory input is very limited, because it can only account for the immediate surroundings at any one time. In order to provide consistency beyond the immediate surroundings, beliefs come into play to provide information necessary to survival.

“Belief” is the name we give to the survival tool of the brain that is designed to augment and enhance the danger-identification function of our senses. Beliefs extend the range of our senses so that we can better detect danger and thus improve our chances of survival as we move into and out of unfamiliar territory. Beliefs, in essence, serve as our brain’s “long-range danger detectors.”

Functionally, our brains treat beliefs as internal “maps” of those parts of the world with which we do not have immediate sensory contact.

… The ability of belief to extend contact with the world beyond the range of our immediate senses substantially improves our ability to survive.

… Because beliefs do not require immediate sensory data to be able to feed valuable survival information to the brain, they have the additional survival function of providing information about the realm of life that does not deal directly with sensory entities. This is the area of abstractions and principles that involves such things as “reasons,” “causes,” and “meanings.”

… Because senses and beliefs are both tools for survival and have evolved to augment one another, our brain considers them to be separate but equally important purveyors of survival information. The loss of either one endangers us. Without our senses we could not know about the world within our perceptual realm. Without our beliefs we could not know about the world outside our senses or about meanings, reasons, or causes.

This means that beliefs are designed to operate independent of sensory data. In fact, the whole survival value of beliefs is based on their ability to persist in the face of contradictory evidence. Beliefs are not supposed to change easily or simply in response to disconfirming evidence. If they did, they would be virtually useless as tools for survival.

… As far as our brain is concerned, there is absolutely no need for data and belief to agree. They have each evolved to augment and supplement one another by contacting different sections of the world. They are designed to be able to disagree.

… When data and belief come into conflict, the brain does not automatically give preference to data. This is why beliefs-even bad beliefs, irrational beliefs, silly beliefs, or crazy beliefs-often don’t die in the face of contradictory evidence. The brain doesn’t care whether or not the belief matches the data. It cares whether the belief is helpful for survival. Period.

Like I said, it’s a great article and deserves to be read in its entirety.