Sadism is a term which describes the experience of taking pleasure in inflicting pain, humiliation, degradation, cruelty, or watching others inflict these behaviors on someone else. Often this pleasure is sexual in nature although this isn’t always the case. People who take pleasure from these acts are known as sadists.
The term sadism comes from the name of the French writer Marquis de Sade who was famously imprisoned after performing sadistic acts on prostitutes. German-born psychiatrist Richard Freiherr von Krafft-Ebing coined the term in his landmark work Psychopathia Sexualis: eine Klinisch-Forensische Studie (Sexual Psychopathy: A Clinical-Forensic Study).
While sadism can be part of a healthy personality, particularly if it only occurs in a sexual context, it may also be a symptom of Sadistic Personality Disorder.