Where does this tribalism and polarization take place if not online? Do you have any evidence of changed patterns in "real life" with that regard? So if Faceboo

Where does this tribalism and polarization take place if not online? Do you have any evidence of changed patterns in "real life" with that regard? So if Facebook keeps people in bubbles so they never get exposed to other views how do you know they are more polarized if not using social media.