The Journey to Error Proceeds One Step at a Time

This from a post at The Panda's Thumb. The focus is on how good Christians wander into such bad science -- it's talking about the Intelligent Design cul-de-sac -- but it is certainly applicable to other things in this political season:

We slip into self-deception by means of tiny steps, each one of which is so small that we can in a sense ignore it, excuse it, not notice it. We creep up on ourselves gradually, thus enabling the story to evolve so slowly that we can justify ourselves in noticing the development. The techniques used are:

(i) Screening. This means that we select from all the information available to us that which is consistent with the beliefs we would like to have. We fail to hear the discordant notes.

(ii) Weighted evidence. We give greater weight to the evidence which supports what we want to believe about ourselves, and we discount the evidence which points in the other direction. Evidence that supports our self-interest is seen as logical and compelling.

(iii) Confirmation. Our attention is quickly drawn to little bits of evidence which confirm us in our false beliefs. Events which confirm us become significant and are remembered whilst those which might appear to have disconfirmed the event are quickly forgotten or regarded as insignificant.

(iv) Gradualism. We do not take too big a step at once because this would be difficult to deny.

(v) Refusal to review the evidence. We do not subject our preferred beliefs to periodic review in order to update them, and thus face the possible risk of invalidation.

(vi) Habit. These tricks of thinking and judging become habitual with us so that we gradually lose the very skills of self-critical knowledge. We become habituated in patterns of thought which contribute to and maintain us in our self-deception.