According to a study published in Nature a few weeks ago, men actually take pleasure on experiencing their "enemies" suffer. In the study, examiners looked at the brain activities of volunteers while they watched people who'd cheated them being physically punished. While on women this aroused the areas of the brain known to be linked to empathy, on me it stimulated the pleasure zones of the brain.
More info on the study at The Times
While the punishment given to the "enemies" on the study was mild - an electric shock supposed to hurt as much as a bee sting - I wonder if this starts to explain how widespread the use of torture is. Most expert interrogators - even those at organizations such as the FBI and the CIA - will be the first to say that torture does not shield useful results. And indeed, at Abu Ghraib and other areas we saw American security forces torture victims without any practical reason.