This NYT piece looks at why one person might jump to save a total stranger from an approaching subway train when most people wouldn't.
When Mr. Autrey saw the stranger, Cameron Hollopeter, 20, tumble onto the tracks, his brain reacted just as anyone else’s would. His thalamus, which absorbs sensory information, registered the fall, and sent the information to other parts of the brain for processing, said Gregory L. Fricchione, an associate professor of psychiatry at Harvard Medical School. Mr. Autrey’s amygdala, the part of the brain that mediates fear responses, was activated and sent sensory information to the motor cortex, which sent it down for emotional processing. His anterior cingulate, a sort of brain within the brain that helps people make choices, kicked in, helping trigger his decision about how to act, Dr. Fricchione said.
But what happened next is harder to explain.
“Propensities to help others are not necessarily based on rational calculations; in fact, they often cannot be, because rational calculations would have been too slow in this particular case,” David Sloan Wilson, an evolutionary biologist at the State University of New York at Binghamton, wrote in an e-mail message. “Instead, they become impulses that are followed spontaneously, either by virtue of genetic disposition or childhood/cultural training.” Still, Dr. Wilson said Mr. Autrey exhibited an extraordinarily high degree of “other-oriented” behavior. “He’s a rarity,” Dr. Wilson said.
That Mr. Autrey served in the Navy most likely played a role, too — he had been trained to act quickly in adverse situations. Acts like jumping in front of trains to rescue strangers are easier for people who are prepared, said Michael McCullough, a psychology professor at the University of Miami. ...
No single factor explains heroism, said Samuel P. Oliner, a sociology professor at Humboldt State University in Arcata, Calif. Yet in interviewing Holocaust rescuers and 911 responders, he found that people who acted heroically often came from more nurturing families and were imbued with an ethic of caring, empathy and compassion.
“The other people, the bystanders, are not bad people,” Dr. Oliner said. “But they have been cut from a slightly different cloth.”