Philanthropy's New Math

By STANLEY N. KATZ

There I was, sitting at my computer wondering how to begin an essay on recent developments in philanthropy, when the daily summary from The Chronicle of Philanthropy lit my screen: "To examine the interplay of self-interest and altruistic behavior, researchers at the National Institute of Neurological Disorders and Stroke, in Bethesda, Md., studied the brain activity of 19 men and women, each of whom was given $128 and asked to make choices about whether to keep the money for themselves or to