@Meanlucario
It’s pretty safe to assume death, retaliation and incarceration is up there in the list of fears for most people.
Knowing that police officers can lock you up for a sentence longer than your current life, or that they can put a bullet in your spine if you try to run, is a pretty good reason not to inflict violence on others.
Lack of fear for ones own life is rare, and often faked to come off as crazy. There isn’t much biological basis for someone who really doesn’t care, and I think a lot of suicide is impulsive.