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.