Look at troops and cops, violent reactionaries who get PTSD because of inflicting harm onto others, even if it gives them enjoyment in the moment. I don't think humans are hardwired to hurt and kill without some kind of remorse, but society teaches us to bury that shit. I even think the covid pandemic is going to leave a lot of people who were otherwise mentally healthy unwell, due to the sheer stress and misery of hearing about so many dead and sick.