To begin, it's about trying to understand a particular ISTJ I know of. I'm an INTP and my sister is an ISTJ. I know we do have quite a few differences that I could understand in terms of making decisions, but sometimes there are habits of hers I don't quite get and hope that I could get some answers from you fellow ISTJs. I do understand that everyone is different, even if they share the same MBTI. Even though, I wish to have some opinion on what you guys think. My ISTJ sister is probably pretty strong on the J: She always complains about sheets that have a tiny crease, if something looks messy to her in her own room, while it looks perfectly clean to others, and she takes a long time to do her bed because she dislikes creases. Even if I accidentally have my hand leaning on her bed while speaking, she believes I'm trying to pick an argument with her because of the crease it's left. She's also pretty quick to act if something isn't done the way she wishes it to be (100% accurate). And she did actually take the MBTI quiz and got ISTJ. Her enneagram is type 1 though I'm not sure about the wing, if it helps. I'm just wondering if there is any special reason she's that way, and how I could change my approach in acting around her. I have asked her, but she just sighed and complain about how INTPs are lazy and ridiculous.