The Frontal Cortex has a fantastic piece discussing a new study finding that people choose TV news based on which channels are more likely to agree with their pre-existing opinions and how we have a tendency to filter for information that confirms, rather than challenges, what we believe.
Lehrer discusses various ways in which we selectively attend to information we agree with but the best bit is where he goes on to discuss a wonderful study from 1967 where people demonstrated in the starkest way that they’d rather block out information that doesn’t agree with their pre-existing beliefs.
Brock and Balloun 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. Later experiments by Brock and Balloun demonstrated a similar effect with smokers listening to a speech on the link between smoking and cancer. We silence the cognitive dissonance through self-imposed ignorance.