Are Poor People Poor Because They Are Too Generous?

So here's a question that has been on my mind for a while. Are poor people poor because they're too generous with the little they have? Are rich people rich because they (generally speaking) are not willing to part with anything they have?

I have had two life experiences that lead me to this question. When I was young I worked as a pizza delivery guy on the side for about a month. On the wall of the pizza place was a large map so that we could see where we needed to deliver our pizzas. Each time a pizza was ready to be delivered, the next guy in line would go get it, look at the address, find it on the map and leave.

We knew which part of the map represented the rich neighborhoods and which represented the middle class and poorer areas. When we would see that the address to which to deliver our pizza was in the rich area, we would groan. We knew we would come back from the rich person's house with little or no tip. The poorer the home, the higher the tip was generally. When the doors to the rich homes would open, I would see a lot of fancy things, but I guess buying all those luxuries meant there was no money left for a tip. Once I delivered 12 pizzas to a party at a rich person's home. My tip? A big fat zero. The owner there said, "Oh, sorry, I don't have enough for a tip." I wondered why then he hadn't ordered 11 pizzas so he would have enough left over to compensate me, the driver.

Another time when I was young I volunteered to go door-to-door to seek donations for a boy in our neighborhood who needed a new liver. He suffered from a rare childhood disease and would die without a new liver. We needed to raise about $40,000 and I joined a group that canvassed the town. We made our goal. The boy got his new liver. He lived.

While canvassing, I found out that the richer the home, the more quickly the door would get slammed in my face. The poorer the home, the more willing they were to share what little they had to help the boy. Some of he poorer folks had real concern in their eyes and would ask for details about the boy, saying they would also pray for him, asking if they could help the family also with meals and such. The rich? Some of them handed over a couple of bucks, most of them wouldn't even talk to me.

So is it a vicious cycle? The poor stay poor because they're too generous? The rich stay rich because they're too stingy?

I know that there are no generalizations here. There are many generous rich people and there are many poor people that would not give a penny to a good cause. But am I wrong to think that in general my thinking is right?