Behavioral inhibition, often displayed as shyness in children and avoidance in animals, can be observed in the earliest stages of infancy. Recent research indicates that in extreme cases the tendency to either approach or withdraw from uncertain events continues through late childhood and is supported by specific biological mechanisms, suggesting a genetic basis. To effectively study behavioral inhibition, researchers are departing from the essentially experiential and descriptive techniques of traditional psychology and turning to a multidisciplinary approach that integrates psychology, psychiatry, epidemiology, genetics, and ethology. Perspectives in Behavioral Inhibition brings together the most current research of leading scholars in the various disciplines involved.