[trusting]

FTT - I think in some cases it is hard to pinpoint, especially if there aren't things that are glaringly obvious.  My H's case is the same way, and maybe if he were to talk to a therapist who knew the things to dig for, we might figure it out.  I used to NEED to figure it out, and I am finally accepting (mostly) that it is what it is and I may never know this side of heaven.  I do have some general ideas and do know that my BIL is and always has been a mess as an adult so there is something there I believe . . .  I still would like to know.  Understanding definitely helps.

The fact that your MIL may not have been able to fully attach emotionally to your H as a child makes sense after all those miscarriages.  My heart ached for her reading about that and then the death of another child later on.