All the world loves a lover. All the world also loves an altruist, someone who gives time, money or assistance to another. In "The Altruistic Urge," Stephanie D. Preston explores how and why we developed -- at least some of us and under certain conditions -- a surprisingly powerful drive toward helping others.

. . .

When anthropologist Margaret Mead was asked to identify the first sign of human civilization, it's said that she referred to a prehistoric fractured femur that had healed. Given the time required to mend such a debilitating injury, this ancient ancestor would not have survived without an immense amount of care provided by others. We are a complex species, impossible to pigeonhole: sometimes painfully selfish but also laudably giving, at times cold and selfish but at others wonderfully generous, not only with time or money but even life and limb.

Ms. Preston's book develops a plausible hypothesis to explain the extraordinary, heart-warming side of our dual personality. Her "altruistic response model" is based on the widespread instinct of adults to care for offspring. This inclination is not limited to parental tendencies, though it appears to have derived from them. Nor is it unique to mothers or even human beings. The author writes: "I decidedly do not try to explain our broad swath of human goodness. I simply make the argument that there exists a specific type of altruism that has persisted in our genome for quite a long time and exists across species, one that powerfully influences our motivation to help -- even heroically."

. . .

Read the full article in The Wall Street Journal