Very true. I have coworkers who I only found out years later were wealthy through family money. They worked as hard as anyone else, and no one had any reason to know they were wealthy.
Just did some googling on this. For the most part, there doesn't seem to be much research on inheritance & personality disorders, which is odd because 'does money make us happy' is one of the biggest questions in sociology. I did find this paper however, which is full of tangential information:
