The United Way helped Vincent Lau when he was a teenager. Now he donates to them. "I'm glad to help, " Lau says.
Workers at the meat packing plant where Lau works make on average around $35,000, yet the Sioux Falls United Way says it gets more contributions of over $500 from employees here than anywhere else.
Another employee at the plant, B.J. Motley, has a wife and four kids to support, but he gives part of his paycheck to charity every week
"My mom always says 'it's always good to give,'" he says. "[I've] got a great family and I've been blessed."
And what about the middle class? Well, while middle-income Americans are generous compared to people in other countries, compared to the rich and the working poor, they give less. "The two most generous groups in America are the rich and the working poor," says Brooks. "The middle class give the least."
Finally, the single biggest predictor of whether someone will be charitable is their religious participation.
Religious people are more likely to give to charity, and when they give, they give more money: four times as much. And Arthur Brooks told me that giving goes beyond their own religious organization:
"Actually, the truth is that they're giving to more than their churches," he says. "The religious Americans are more likely to give to every kind of cause and charity, including explicitly non-religious charities."
And almost all of the people who gave to our bell ringers in San Francisco and Sioux Falls said they were religious or spiritual.
So how did our little test turn out? Tune into a special edition of "20/20," "Cheap in America," to find out.