In this popular American book from the 1920s, accomplished public speaker and self-help charlatan Elsie Lincoln Benedict outlines her pseudo-scientific system of "Human Analysis". She proposes that, within the human race, five sub-types have developed through evolutionary processes, each with its own distinct character traits and corresponding outward appearance. She offers to teach the reader how to recognise these five types of people and understand their innate differences. Her ideas have never been taken seriously by the scientific community, but this book is considered a classic within its genre and remains in print today.