Confirmation bias is the tendency to...
- search for
- interpret favorably
- recall information
... data/evidence in a way that confirms or supports one's prior beliefs or values.
This reinforces preexisting beliefs - once a belief is formed, people favor information that confirms the belief. And reject evidence that throws doubt on it.
This effect is stronger for deeply held beliefs, identity topics, or strong emotional triggers.
Confirmation bias is an implicit tendency to notice information that coincides with our preexisting beliefs and ignore information that doesn't while motivated reasoning is our tendency to readily accept new information that agrees with our worldview and critically analyze that which doesn't.