The logic of modesty -- why it pays to be humble. Why do people make anonymous donations, and why does the public perceive this as admirable? Scientists have developed a novel game theoretic model that captures these behaviors and enables their study. Their new model is the first to include the idea that hidden signals, when discovered, provide additional information about the sender. Source 9d.
While I do good things now and then it does not necessarily involve donations. I have made clothing donations and furniture donations but not monetary donations. I do pay it forward at times by going through a drive through and pay for the person behind me or even the the two behind me at times. I feel that helping now and then can be good and if I do it and stay anonymous then it is nice too.