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.
Asking why you're getting downvoted is usually the easiest way to get downvotes.
But I often wish I would get a comment about downvotes. It's easy enough to see why I'm getting downvoted when I post stupid shit, but sometimes I feel like even the most uncontroversial post or comment will get at least one downvote. I want to know when I'm wrong, so I can learn!
Like, the other day there was a post getting downvoted to oblivion and nobody told OP anything. I commented my reason and OP actually seemed to be learning from that, edited the post and the downvotes stopped accumulating.
I had a conversation with someone about one of my downvotes posts, which helped to understand yet another stupid derailing tactic that terrible people use to stifle conversation. I really appreciated their feedback, even if I didn't see any way to avoid the misunderstanding.
I've seen completely normal and innocuous statements heavily downvoted here. Some people seem to just downvote everything and other people seem to downvote anything that already has downvotes. But one thing is for certain, it's treated as a like/dislike button, not as a meter for content that does or doesn't contribute to the subject.
I don't think either of the popular behavior descriptions of "upvote if it contributes" or "upvote if you like it" really describe why most people upvote/downvote. My personal downvote criteria is more of a checklist:
Is it unnecessarily cruel?
Is it misinformation, or significantly misleading?
Is it something so tired and overused that I don't think it should be posted?
Is it completely nonsensical?
Etc.
If any of those are true, depending on the severity I'll leave it be or downvote. I'd imagine most people are similar.
Those are all reasons I downvote too, but I'd lump them all into the "doesn't contribute to the conversation/community" category. I'll also report something if it's dangerous misinformation, or very hostile towards an individual.