 To that hydraulic model, Freud adds several questionable claims derived from his general psychoanalytic theory of the mind. He says that the creation of der Witz—jokes and witty comments—is an unconscious process of letting repressed thoughts and feelings into the conscious mind. This claim seems falsified by professional humorists who approach the creation of jokes and cartoons with conscious strategies. Freud’s account of how psychic energy is vented in joke-telling is also questionable, especially his claim that packets of psychic energy are summoned to repress thoughts and feelings, but in statu nascendi (in the process of being born) are rendered superfluous. If Freud is right that the energy released in laughing at a joke is the energy normally used to repress hostile and sexual feelings, then it seems that those who laugh hardest at aggressive and sexual jokes should be people who usually repress such feelings. But studies about joke preferences by Hans Jürgen Eysenck (1972, xvi) have shown that the people who enjoy aggressive and sexual humor the most are not those who usually repress hostile and sexual feelings, but those who express them.