In a neurological study cited in Science, human research subjects were placed in an MRI (magnetic resonance imaging) scanner and manipulated through situations in which they gave charitable donations. Some brain regions involved in reward were activated by giving, indicating that the brain was experiencing positive sensations from the act of giving.
"If you look at human financial behavior as an attempt to increase the feeling of reward," said a neuroscientist, "then donating money makes economic sense. Look at it this way: when I'm giving to charity I'm paying for the pleasure of donating money."http://tinyurl.com/yu4rhe