1 They feel financially insecure
Many rich people feel financially insecure because they were raised in families that had serious financial difficulties. Those rich people might still feel insecure and unsafe about the future even after they become rich.
2 They fear the future
Some rich people are too afraid of the future and of losing their wealth. Those rich people are more likely to be stingy than other rich people who don't share those beliefs.
3 They are selfish
Selfish people hate giving and feel bad when they give things to others. When a selfish person becomes rich, they are very likely to be stingy as well.
4 They can't empathize with poor ones
A rich person might have a hard time empathizing with a poor person, as they might find it hard to imagine how this poor person feels. This lack of empathy can prevent the rich person from giving to the poor.
5 They think poor people are lazy
Egocentric rich people who believe that they made their own wealth because of their great personal qualities might blame poor people for being poor and thus become less motivated to help them. (See Why are some rich people unhappy?)
6 They don't have a reason to give
Some religious people might have a religious motive that motivates them to give money to the poor. If a person doesn't have a good reason to give money then they might not feel like giving.
7 They are very materialistic
Some rich people are very materialistic. They love money, are obsessed with it and hate to give away any of it. (See Why do rich people like to play golf?)
8 They earned money the hard way
Rich people who exerted a lot effort to get their money might not feel like giving because of believing that others must work hard as well to get money.
9 Their business is not going well
A rich person can feel unsafe if their business doesn't go well. In such a case, the person might get more stingy during that phase.