More than most textbooks in psychology, this book reflects the work, the life, and the personality of its author. After forty prolific years of boldly original research and theorizing on the topic of human motivation, David McClelland has not produced a conservative, homogenized, and middle-of-the-road review of the literature. Like Personality, McClelland's classic textbook on personality psychology written over thirty years ago, this text takes some risks. First, the book does not aim to review all of the important literature on human motivation; rather, it seeks to explore in some detail a selected set of critical and intriguing motivational issues. Second, the book does not merely summarize theories, methods, and research findings pertaining to the scientific study of human motivation; rather, it attempts a theoretical synthesis of its own based on the author's particular perspective on human motivation—a perspective that has developed through a number of stages during the last forty years.

David Winter (1982)—a Student and colleague of McClelland—has recently traced McClelland's intellectual biography as a psychologist through six stages. From his rigorous training within the behaviorist tradition of Clark Hull at Yale and his early research on verbal discrimination learning, McClelland moved to the study of thematic measurement of psychological motives (such as the achievement motive) in the late 1940s.