To simplify things; if you inherit it, you're stingy. If you earn it, you're more charitable. And thus this simple rule was confirmed by Alice D Camel when she sent me this chart;
I've had theories about this, but it basically boils down to that unless you started off poor and know the challenges and how difficult it is to become rich, you really are incapable of genuine sympathy. Thus why those who inherit their wealth are not so generous with it, because, we'll, "how hard is it to become rich? I am and, why I just sat here."
However, tangential to this theory is also why leftists who are rich, tend to insist that the poor must be helped, but much prefer to force you to be charitable with YOUR money, rather than theirs. It is no coincidence communist intellectual titans such as Marx and Che Che were spoiled little brats, born with silver spoons in their mouths. They never had to work, they were trust fund babies. And having such a life of luxury afforded them the genuine intellectual luxury of advocating socialism and communism. They never had to work. They never had to strive. All they had to do was in order to sound cool and hip and intellectual was advocate a new economic system that would transfer the wealth from the producers to the parasites...err....I mean the "have's" and "have not's." Of course, they still had to be in command and be members of the elite in this new society, but they "cared" about the people.
Sadly you can see this strain or viral thought in many elite or "limousine liberals" today.