Writing for Wired.com, Jonah Lehrer reviews research on belief and perception:
It turns out that the human mind is a marvelous information filter, adept at blocking out those facts that contradict what we’d like to believe. Just look at this experiment, which was done in the late 1960’s, by the cognitive psychologists Timothy Brock and Joe Balloun. They played a group of people a tape-recorded message attacking Christianity. Half of the subjects were regular churchgoers while the other half were committed atheists. To make the experiment more interesting, Brock and Balloun added an annoying amount of static – a crackle of white noise – to the recording. However, they allowed listeners to reduce the static by pressing a button, so that the message suddenly became easier to understand. Their results were utterly predicable and rather depressing: the non-believers always tried to remove the static, while the religious subjects actually preferred the message that was harder to hear.