From the Editor; December 2004; Scientific American Mind; by Mariette DiChristina; 1 Page(s)

Last night something happened for the first time in my 17 years of commuting by rail. As the train began rolling north, I concentrated on proofreading pages of the magazine that you now hold in your hands. Slowly, it dawned on me: "I left my purse in my office," I said to no one in particular. No ticket, no money, no ID--and no one I knew in sight to help me out. The conductor was headed down the aisle, and I wondered if I'd be tossed out at the next stop, leaving me miles from office or home. Then the woman across from me leaned forward. "Can I buy your ticket for you?" she asked. A man sitting two seats over from her added, "Do you need a ride home when we get to the station?"

Researchers have been puzzled about why such altruism, so frequently and generously offered, should exist at all. In a Darwinian world of "survival of the fittest," why do perfect strangers volunteer to help, even when such aid may come at a cost to themselves? Why purchase a ticket or expend gas and time driving a hapless commuter home? Seeking answers, scientists probe our behavior in experiments designed to reveal the roots of altruism. The cover story of this issue, "The Samaritan Paradox," by Ernst Fehr and Suzann-Viola Renninger, on page 14, describes how altruism emerges spontaneously even in anonymous exchanges among people, whereas animal altruism starts and ends with kin.