Brains are hardwired to act according to the Golden Rule

Wesley Autrey, a black construction worker, a Navy veteran and 55-year-old father of two, didn't know the young man standing beside him.

But when he had a seizure on the subway platform and toppled onto the tracks, Autrey jumped down after him and shielded him with his body as a train bore down on them. Autrey could have died, so why did he put his life on the line - literally - to save this complete stranger?

Donald Pfaff, the author of the new book The Neuroscience of Fair Play: Why We (Usually) Follow the Golden Rule, thinks he has the answer. Our brains, he says, are hardwired to do unto others as we would have them do unto us. Individual acts of aggression and evil occur when this circuitry jams.

"If it's really true that all religions have this ethical principle, across continents and across centuries, then it is more likely to have a hardwired scientific basis than if it was just a neighborhood custom," says Pfaff, whose laboratory at Rockefeller University studies various hormones and brain signals that influence positive social behavior.

In his book, Pfaff proposes a theory that explains, in a parsimonious way, how people manage to behave well when they do, and under what conditions they deviate from good behavior. He describes how memories of fear, as well as various brain hormones, can play a vital role in whether people choose to act ethically or violently toward others. One's behavior is a balance, he says, between prosocial and antisocial traits a balance shaped by early life experiences.

You have some people who are prosocial, who face the world with a smile and are uniformly nice to other people, says Pfaff. "Others face the world with a snarl and are routinely aggressive and thoughtless. Most of us are a balance - we are able to treat each other almost all the time in a civil and thoughtful way." But nobody's perfect, he adds. Even those in the prosocial group have cheated on their taxes.

Donald W. Pfaff, Ph.D., is professor and head of the Laboratory of Neurobiology and Behavior at The Rockefeller University, a member of the National Academy of Sciences and a fellow of the American Academy of Arts and Sciences. At Rockefeller, where he has studied the brain and behavior for more than 30 years, he discovered the brain-cell targets for steroid hormones and proved that these chemicals, among others, could elicit specific behaviors when reaching the right brain areas. He has served as editor, or on the editorial board, of 21 journals and is author or editor of 16 scientific books and more than 700 scientific articles.