Confirmation bias (also called confirmatory bias or myside bias) is a tendency for people to favor information that confirms their preconceptions or hypotheses regardless of whether the information is true.
It is a type of fallacious thinking where people tend to pay more attention to arguments that suit their way of thinking or belief system. I think it is a form of ambiguous thinking, or a sort of bias thinking
It has to do with how we process new information. Current research indicates, that not only do many people accept or reject new information based on how well it conforms to their pre-existing beliefs/ opinions, but that information which contradicts those pre-existing beliefs/opinions actually reinforces those beliefs/opinions.
This can be clearly seen in debates between the religious and the non-religious.
The religious are not only impervious to the logic and facts put forward by the non-believers, but they walk away more convinced than ever that Satan and his minions will say anything to undermine their faith, and congratulate themselves on how strong their faith is and how well they resisted Satan's wiles.
The non-religious not only tune out when people quote scripture at them, their pre-existing belief that such people couldn't come up with an original thought of their own to save their lives is reinforced.