What sort of post or comment gets you downvoted the most? Especially if you don’t think it’s bad behavior in the first place, or don’t care. Does not have to be on Lemmy, but we are here…
One of the good things about Lemmy IMO is that it’s small enough to see the posts that are unpopular. If you do “Top Day” on most channels, you cash reach the bottom, see what people here don’t like.
As far as comments, attempting to rebut the person who is telling me my post sucks, is what gets me into negative numbers most often. The OP is going to voite it down, of course, and nobody else cares, usually.
I reckon it’s the issue of pseudo-anonymity combined with the lack of tone in a text post. If you’re talking IRL it’s much clearer that you’re making a joke or whatever, but all that gets lost in text. Also you generally know who you’re talking to IRL, whereas online you don’t know if that comment was written by a professor of ethics or a teenager who watched a single video on the topic and is parroting opinions they are now convinced are correct.
That’s why I really like the /s marker, unfortunately it gets a lot of hate.