How would one call something negative interesting?

Question

This seems like it is very basic, but it was never resolved in the past, so here I am.

This was in a Reddit post recently, but it never received a good answer; most of the answers were along the lines of "I wouldn't call an old war story with sad elements 'interesting'," "just use「そうなんだ」or「なるほど」、" and things like that.

Essentially, I want to be able to call something interesting in its own right without any connotations of amusement. That way, if I encounter something that would upset the speaker to be amused by it yet still find the subject matter to be interesting to all audiences, I can reply with such.

Answer 1

Is the word "interesting" (or its Japanese counterpart, whatever it is) something you insist upon? It's a word that by definition suggests a positive evaluation. Sure, it doesn't have a "funny ha-ha" kind of connotations but if, for example, someone told you about a sad, tragic or serious event and you responded with "Oh, that's interesting./それは興味深い話ですね。" you probably deserve to be accused of insensitivity, if not frivolity, even if said event did have some interesting aspects. (Although a lot depends of the context, like how sad/tragic/serious the event is, whether it's a true story or fiction, who the teller is, and what kind of reaction is expected by them.)

If you want to use it and still make sure you are not misunderstood, I think you have no choice but to carefully state what you mean and do not mean by it in so many words.

But if you'd rather spare words, and can do with something other than "interesting", here's a suggestion:"考えさせられる" ("makes you(/me) think", or "thought-provoking"). It implies more or less serious thinking, and, generally speaking, it's a safer option than "興味深い".

(While I'm at it, let me give you some usage suggestions:「考えさせられる話ですね」「何か色々と深く考えさせられます」「それは考えさせられるところの多い話ですね」)

Answer 2

I don't recommend 興味深い either. That's not safe either because it basically means "I'm curious".

Considering how English speaking youtubers say "hmm, interesting", なるほど… or そうでしたか… seem reasonable to me, but if you are somehow not content with those phrases, how about compromising settling for either of them with "勉強になります"?