I don't see my ISTJ dad engaging with anyone. He observes in a social setting and hangs around, but doesn't expend much energy asking the other person about themselves, nor does he disclose anything that would allow him to get closer to anyone. He would talk about exactly the same kind of stuff with the next door neighbour, a stranger, my mum or one of the grandkids. It's been a family joke that he would have made an excellent spy, due to the evasive kinds of answers he gives even to inoccuous questions. I think he is lonely, but from what I can see doesn't want to expend the energy it would take to get to know any of us better. I've come to terms with it, but I think it continues to be a huge frustration and disappointment to my mother, who is committed to the marriage, but there is very little intimacy of any sort. At this point, she's given up trying a million different ways and concluded it just isn't in him to do it. Do you think this is a result of upbringing/past experiences, or just a natural tendency of his personality type? I realize our household is drenched in Fe (My mum is ENFJ and I'm INFJ). Maybe that contributes? Who knows.