I think the difference is that only individual posts get downvoted here.

I (used to) have friends on FB who will unfriend anyone epxressing an opinion that they don't agree with (or "find offensive"). They end up in an echo chamber where they never hear an opinion they don't already agree with, and then get surprised when elections don't turn out the way they wanted. Weirdly, I'm still friends with some of them irl, and we can have civil discussions about the same topics in person, just not online.

Unpopular opinions on HN get downvoted to invisibility, but the author is still able to post other unpopular opinions. They'll probably also get downvoted, but sometimes they get supported.

>Unpopular opinions on HN get downvoted to invisibility

Do they? In my experience (admittedly limited, a couple of years) things get a lot of downvotes almost always for how they say it, not what they say. Can anyone give counterexamples? A well-expressed comment worth reading but downvoted to invisibility?

I have no idea if there's a perceived difference in how I'm saying things, but I definitely notice that the unpopular opinions I hold get downvoted to invisibility.

Do you have some examples of that? Links? I should do an Ask about it I guess.. Examples seem hard to come by.

check my comment history and see the numerous downvoted comments ;)

Agreed there is a difference. Not so much agreed that it meaningfully suppresses the echo chamber effect. The ultimate result is the same. That which sufficiently differs with the views of the majority of the people on this site tends to be seen less, or not at all depending on the extent of the disagreement. Except for us heretics with showdead enabled.

agreed. But the majority here define the "acceptable" opinions, not the individual.

Also, I've had climate-skeptic comments upvoted and culture-war comments downvoted in contradiction to the dominant narrative here, so it does seem to be post-by-post rather than site-wide chambering.

> But the majority here define the "acceptable" opinions, not the individual.

That doesn't seem better to me. :( You are right that sometimes counter-hive-mind comments get upvoted, though, if written just the right way. I hope this happens more often in the future.