I've never seen any evidence that the "poor" (or even the "middle-class"), taken all together, are any less ambitious, greedy, suspicious, or unscrupulous than the "rich." They just don't have the resources to be very good at it. (Of course, some do become successful mobsters - because of those very qualities.)

A hundred and fifty years of history, psychology, and anthropology seem to have exploded Rousseau's idea, which became the ultimate foundation of Marxism, that men and women are naturally benevolent until corrupted by ambition and greed.

The greed and ambition start developing at birth, along with the benevolence.

Neither Hitler, Lenin, Mussolini, Mao, Stalin, or Al Capone were born "rich," and none became ideal moral examples. (Of course the list could be extended.)