I'm having trouble with a particularly unhealthy ISTJ. A few items: controlling, socially inept (which I thought belonged to my personality type... but no, this is a whole other level of clueless), inserts herself into conversations that don't involve her and then acts like she knows answers when she knows nothing on the topic, and hypercritical of others but throws a fit if anyone disagrees with her. For instance, I called her out (carefully, but that doesn't matter) on something she inserted herself in where her comment was actually detrimental (normally I ignore it) and now she's off fuming. Her response to me was that it's my fault because what she read didn't provide a full history and description of the entire issue-- keep in mind, this was a series of comments I was having with someone she doesn't even know on a topic that has nothing to do with her. How do I communicate "what you did is not socially appropriate" without making things worse?
In summary, this has been going on for years and I'm on the verge of losing it, which would probably involve yelling "for the sake of everyone who has to put up with you, why don't you go sign up for a social skills class?" ... which would not end well.
For those of you who might have more insight into how her mind operates-- is there an effective way to get an unaware ISTJ to understand boundaries?