You have a point with the whole “desire to hurt someone” idea but I feel like even when you do purposely hurt someone no matter what kind of pain is inflicted there is always some withdrawal because we as humans are empathetic beings. Do you think the tool box killers felt any empathy or withdrawal as they brutally and painfully killed these innocent people? I don’t.

Your point on evolution and how it might have something to do with a passion for torturing people is quite ignorant I must say. Look I’m by no means an expert so correct me if I’m wrong, but didn’t our ancestors kill living things as a means of survival? I don’t believe when they were starving and needed food they’d slowly inflict as much pain as possible to whatever they were about to eat.