David G. Myers and Letha Dawson Scanzoni

An affirmative answer to Reinhold Niebuhr's famous prayer begins with the wisdom to distinguish what we can change from what we cannot. Some traits, it's now clear, are naturally predisposed and not amenable to change; other characteristics lie within our control. Our temperament is one trait that we receive rather than choose. From womb to tomb, some people tend to be excitable, intense, and reactive; others are easygoing, quiet, and placid. People may mellow a bit with age, but the…