I don't know, but I bet that most of these bank holdups are not the folks out of their homes and p-o'd at the banks. It's part of the changing social mores and the way that more and more people feel disenfranchised from society so do not have any compunction about damaging other people's dreams.
I wonder whether we can find some research about this group of people that would give us an idea of who they really are. Maybe the FBI website - they have some good articles in their bulletin.
FBI
September's issue has a good article on "Street Gang Mentality."
Here's a link to
unknown bank robbers.
This article is from 1997 but it gives some a little info on who bank robbers were turning out to be
bank robbers