Via the @BCAMT email list-serve:

"[T]here is an interesting (and disturbing) literature on situations in which information does not change prior biases or decisions. The word I have seen is ‘motivated reasoning’.

Interestingly, I ran into a problem of ‘motivated reasoning’ with a class of future teachers. The question is: when would research about the teaching and learning of mathematics change their classroom practices. A common response to articles, given some practice in critiquing research, was:\

– if I agree with the conclusion, the article was reliable;
– if I disagree with the conclusion, then here are x reasons why the article was not reliable and I should not change my practices!" 

Dr. Walter Whiteley

Dr. Whiteley works with pre-service teachers, and would like me to point out that they are still in the middle of articulating their own personal theories of how learning and education work, thus they lack experience in schools from the other side of the desk. It is therefore possible that this is an issue isolated to pre-service teachers.

On the other hand, I have seen people vehemently defending a position that has no merit simply because they are unwilling (or unable) to see that the evidence is mounted against them. I have also noticed many times that months later, this person has changed their perspective, sometimes claiming that the opposite to what they had previously believed was their belief the whole time, so maybe that argument influences their thinking later, and they are more willing to change on their own.

It takes enormous strength of will to remind ourselves of our cognitive biases, and act against our instinct to defend our mistakes. I can’t say I’ve succeeded at this all that much. Does anyone?