Good column on how we interpret information according to our pre-existing ideas:
Another challenge is the biased way in which we gather information. We seek out information that reinforces our prejudices. One study presented listeners with static-filled recordings of speeches that they believed they were judging on persuasive power. Listeners could push a button to tweak the signal, reducing the static to make it easier to understand. When smokers heard a speech connecting tobacco with cancer, they didn’t try to improve the clarity to hear it more easily. But they pushed the button to get a clearer version of a speech saying that there was no link between smoking and cancer. Nonsmokers were the exact opposite.