For me personally the first tell is when they are morally loading every statement in an argument and are unable to engage with a topic directly. Adults should be able to discuss or debate certain topics on the value of the arguments alone without feeling pressured to include a declarative virtue signal in every clause.
Usually when discussing a heated topic (politics, gun control-take your pick) and trying to discuss the facts of the matter in a neutral manner but the response comes back with every phrase super charged with morally loaded words. Examples of a conversation I had recently (emphasis mine):
sure as hell isn’t PANDERING! What the fuck is wrong with you??
Typical apologist tactic
PRETENDING to care about the brutal slaughter of tens of thousands of innocent civilians
deflecting to your conspiracy theory
shows that YOU don’t care enough about Palestinian lives
It's very pronounced on this site for some reason. I don't know why.
"debate me" kids are another stereotype on the internet though. The idea that ideas should be entertained and discussed for the sake of it and come without implications attached is just another form of edgyness. It's another thing that often goes away with age or with touching grass. I know because I was one of them. Now I understand that the fact itself of discussing something publicly has moral implications.
Yea, I agree. That's why I used the word discuss because when the debate-bro mindset kicks in you're definitely dealing with an angsty teenager (also the constant invocation of logical fallacies).