Sadism is the tendency to derive pleasure, gratification, or a sense of power from inflicting physical or psychological pain, suffering, or humiliation on others.
The term spans clinical and everyday usage. In clinical psychology, sexual sadism disorder describes recurrent arousal from inflicting suffering, classified as a paraphilic disorder when it is acted on non-consensually or causes the person distress or impairment. Separately, 'everyday sadism' describes a subclinical personality trait — a disposition to enjoy others' pain that exists on a continuum across the general population rather than as a diagnosable condition.
In personality research, everyday sadism is often grouped with narcissism, Machiavellianism, and psychopathy to form the 'dark tetrad,' a cluster of socially aversive traits sharing a common core of callousness and low empathy. Sadism is the trait that distinguishes the tetrad from the older 'dark triad' by adding an appetitive element — taking active pleasure in cruelty rather than merely tolerating it as a means to an end.
The word derives from the 18th-century French writer Marquis de Sade, whose works depicted cruelty as a source of gratification. In common use it is applied loosely to any enjoyment of others' discomfort, and researchers distinguish it from masochism — the derivation of pleasure from one's own pain — with which it is paired in the combined concept of sadomasochism.