Pride and Cruelty

The word 'cruelty' is often used as though it is synonymous with 'sadism.'  As though the only cruel people in the world were those who drowned cats for fun when they were kids and then graduated to doing even worse to their fellow human beings as adults.  The word cruel conjures up, for me, the lurid proceedings of police dramas (Luther is pretty good, but man, it's uncomfortable sometimes) and true crime stories; it's a word for serial killers and the psychopathic enforcers of drug gangs.  Certainly it seems to imply that someone is getting pleasure from someone's pain and death.