Maybe it’s like my experience: They act quite defensive and only hang out with a few people. It seems they feel threatened by “outsiders”. Even when they’re not hurting is, we in turn feel threatened as well. Why is that?

Often, these people themselves are seen as outsiders, maybe picked on, went through trauma, etc. And even I don’t want to feel such a way, but I do feel some sort of “uncanny valley” by their behavior.