This book represents the most complete consideration in Russian psychology of the issue of physiological, psychological and social differences between men and women. The author systematizes domestic and foreign research, including the latest, on the sex and gender characteristics of people. The need for a joint consideration of these features is shown. In addition to discussing theoretical and methodological issues, the book presents methods for identifying gender differences (psychological sex). The publication is of undoubted interest for psychologists, doctors, teachers and students of university faculties of relevant profiles.