Derivation of pleasure as a result of inflicting pain or watching pain inflicted on others, especially sexual partners (see: sexual sadism), and is crucial to sexual arousal and function. Animal abuse or torture may also contribute to pleasure attained in this manner. Usually chronic and seen primarily in men, resultant of conscious or unconscious motivations or desires, and can lead to rape, torture, and murder. May be observable from the initial stages of development, i.e. an infant might attain pleasure from biting during the oral-biting phase of development. See also: anal sadism; oral sadism. Compare with: masochism.