Jerome Kagan, Professor Emeritus of Psychology at Harvard University, has helped to reshape contemporary psychology: he is one of the handful of psychologists who reintroduced the old notion that temperament is a key to a child's development. Today, this might not be such a revelation. But when Jerome Kagan started in 1950 as a graduate student at Yale, the idea that biology or the character traits you were born with had anything to do with how children grew up was pretty revolutionary. His numerous publications, for both the scientific community and the general public, include The Nature of the Child, The Long Shadow of Temperament, and his most recent, An Argument for Mind, which might be called his intellectual memoir.