Generally though, think of "contributing substantively to the discussion" (e.g. providing facts, ideally sourced [1], relevant personal experience, or interesting and neutrally worded questions) as a high good. And tossing around memes, ad hoc attacks, argumentative language without facts, and "contentless" comments as the lowest bad.

And as parent mentioned, the stronger the claim, the more it behooves you to cite a source.

In general, try and write the kind of comments you want to read & treat everyone with respect. :) And hopefully others will do the same!