Confirmation bias is a type of cognitive bias which causes people to favor evidence that confirms their pre-existing beliefs over evidence that would tend to disprove it. This often occurs subconsciously, and the individual doesn't realize it has happened. Some examples would be:
- God answers prayers - A person remembers each time a prayer appears to have been answered, and dismiss any times it hasn't, often with the excuse, "God always answers prayer - sometimes, he says no".
The primary problem with confirmation bias is that it leads to people having warped or "filtered" understandings of the world around them. This can support various erroneous beliefs they may have.