New Yorker writer Malcolm Gladwell looks at why major changes in our society so often happen suddenly and unexpectedly. Ideas, behavior, messages, and products, he argues, often spread like outbreaks of infectious disease. Just as a single sick person can start an epidemic of the flu, so too can a few fare-beaters and graffiti artists fuel a subway crime wave, or a satisfied customer fill the empty tables of a new restaurant. These are social epidemics,...

"On the psychoanalyst's couch...in the Head Start classroom...whether teasing out the mysteries of our own past or trying to brighten our children's future, few of us question the pervasive belief that early childhood exerts an inordinate power over adult achievements, relationships and mental health. Once robbed of our potential by the psychic wounds of infancy or the inadequacies of our upbringing, the theory goes, we risk being trapped in maladaptive...