Boas

Well it  is bias reinforced by everyone sharing it.

So you will try your hardest to save narratives from your side, scrutinize the other side's, less likely to examine the premises of yiur side, or study data which potentially contradicts your side, more likely to be the other sode's argument wrong, more likely to see the best motivations on your side and vice versa even if it is untrue, more likely to promote your own side, more likely to know the best rep for your side and the worst rep for their's.

Stand for injustices against your own, the injustices against the other need to be extra obvious

Nor likely to look the other way for your side and dog the other