A self-serving bias occurs when people attribute their successes to internal or personal factors but attribute their failures to situational factors beyond their control. The self-serving bias can be seen in the common human tendency to take credit for success but to deny responsibility for failure. It may also manifest itself as a tendency for people to evaluate ambiguous information in a way that is beneficial to their interests. Self-serving bias may be associated with the better-than-average effect, in which the individual is biased to believe that he or she typically performs better than the average person in areas important to their self esteem. This effect, also called "illusory superiority" has been found when people rate their own driving skill, social sensitivity, leadership ability and many other attributes.

I've been told that these shields are necessary for the preserving of our self concept and stuff from a clinical psychiatrist. I am not too sure if I agree with her that they are needed. However, I do think we can at least lessen the strength of these shields.