G. Y. Eysenck is a British scientist-psychologist, one of the leaders of the biological trend in psychology, creator of the factor theory of personality, author of a popular intelligence test.K. Bartol is a psychology professor, behaviorist, profiler, and author of the world's most popular textbook on criminal psychology. How did people seriously begin to support the idea of genocide of Jews in the mid-20th century? Were they completely different people? We're not like that, are we? We're definitely better. This is what people usually think when studying the history of World War II, but famous experiments from the 1960s to 1980s say otherwise. Students are divided into two groups, guards and prisoners, and asked to play prison. After a few days, the experiment has to be ended early due to cases of unjustified cruelty. Kind religious housewives are offered to shock a person for incorrect answers, and almost 100% of the subjects bring the shock to lethal levels. Priests are offered a lecture on the importance of doing good and helping people, but seeing a dying person on the way to the audience, almost 100% of lecturers indifferently pass by the person in need of help. Is the world full of two-faced and deceitful people? Is every person a criminal at heart? Or can everyone simply be forced, provoked into the necessary, sometimes criminal, behavior? What underlies the psychology of a criminal and is anyone capable of murder? Leading behavioral psychologists of the 20th century answer this question.