Masturbation (onanism) is the stimulation, often manual, of the genitals for sexual gratification. Masturbation is depicted in prehistoric cave paintings and has been observed in many animal species. In Egyptian myth, the god Atum created the universe by masturbating, and every year the pharaoh ritually masturbated into the Nile. In certain traditional societies, masturbation is a rite of passage into manhood, although there are some populations, notably in the Congo Basin, that lack a word for it and seem