Psychoanalyst Erich Fromm in 1964 developed the term "malignant narcissism," believing it to be the worst form of psychopathology, a disorder that essentially epitomized evil. Malignant narcissism, however, has never been identified as a clinical condition in the ; instead, it is seen as a conglomeration of several other disorders. Yet researchers since Fromm have described malignant narcissists as unique in their callous nature and proclivity to extreme violence, with a component of sadism bringing them pleasure when inflicting pain. The largest concern about malignant narcissists is that "some have the ability and wherewithal to rise to great positions of power and influence" and to affect large numbers of people. Authors Smith and Hung explain the differences between malignant narcissists, "everyday" narcissists, and psychopaths, illustrating these conditions with vignettes of historic public figures and people in popular culture, among others.