It seems that it's part of human nature to "take sides".
We start as kids when we pick teams
South Pacific - "We must be carefully taught".
Politically - we pick a side
in church we're on the "Lord's Side" - otherwise we're part of the "World".
Once we're on a side, we view the world around us as either "us" or "them".
If it strengthens our side, then we welcome the information - if it's against our concepts, then we look to dismiss.
This is a key contributor to the development of Bias.
The power and danger of Like-mindedness