Most of the time both poor and rich gamblers are being move by emotions, even how much the amount they allocate for their gambling without a good control, they can be careless and lose more. Though for some rich gamblers, they have that good limitation inside them as they value their money and not to allow to over exceed from what they can afford to lose, opposite with poor gamblers who are aiming for luck to double what left in their pockets, not all though but most have this kind of thinking.
It's a good thing you mentioned that both sides are humans, and they respond similarly to gambling outcomes. Practice helps players advance to a better level of thought that beats the loss-of-control challenge. The few rich players who limit and control their money didn't just attain that stage. They worked for it, just like they did for their money. Still, on the same page, some low-income players have this value for money and wouldn't go past their limits.