A re-writing of the book which when it first came out in 1939 was a Book of the selection, has had since that time a steady following, and which now includes 60% new material. Here again are the fascinating findings of the plus, and the minus, of heredity and just how and when heredity is directly applicable to human beings. What you do and don't inherit, the determination of sex; the influence of heredity on eye and hair and skin color, on features and figure; the part it plays in the transmission of diseases, functional defects; its calculable effect on longevity, intelligence, talent, genius, behaviour, personality, sexual deviations, crime; the questions of race, ancestry, the birth rate, etc. etc. If clinical, this is always readable and applicable, sometimes personal, sometimes anecdotal, and is based on the most recent statistical data available in the fields of social (Klnsey) and medical research.