How to Spot Potential Heroes

When he saw the baby falling from a third-floor apartment, all Stephen St. Bernard thought was, "Maybe I can catch her." He sprinted over, and the child hit him with an estimated 600 pounds of force, nearly ripping his arm off. He doesn't care. "Not a scratch on that baby," he says. It's one of several heroic stories the Wall Street Journal highlights in a piece asking what separates potential heroes from everyone else. St. Bernard epitomizes one common trait: optimism.

Heroes tend to accentuate the positive, and believe in their own abilities, psychologists say. They often like taking charge, and consciously banish fear. Empathy is another common hallmark, as is a strong moral code. There are physical indicators too; one study showed that people who had intervened in assaults and crimes were generally taller and heavier than others. But those traits aren't everything; the Journal profiles one woman with a debilitating back injury who ran for the first time in 10 years to save an old lady from an oncoming train. (More heroism stories.)