https://www.scientificamerican.com/article/why-social-media-make-us-more-polarized-and-how-to-fix-it/

Every time I log onto Facebook, I brace myself. My newsfeed—like everyone else’s I know—is filled with friends, relatives and acquaintances arguing about COVID-19, masks and Trump. Facebook has become a battleground among partisan “echo chambers.” But what is it about social media that makes people so polarized?

To find out, my colleagues and I ran a social media experiment in which we divided Democrats and Republicans into “echo chambers,” or small groups whose members affiliate with just one political party. Next, we picked the most polarizing issues we could think of: immigration, gun control and unemployment. We asked each participant what they thought of those issues, then let people talk to each other and revise their opinions. After several rounds of discussion and revision, we evaluated each group’s viewpoint.