From the Preface: “This text is a natural history of human nature in the lives of individuals. It contains a discussion of the processes by which the newborn, who does not have human nature, develops into an adult with the characteristics regarded as essentially human. It is designed to reveal how the individual and his social heritage become two aspects of a total situation, so inextricably related that the individual can never be returned to the biologist as a mere potential human, now can experienced aspects of the social heritage be taken from the individual.”