Guys: Would you ever rape and murder a girl?

[God of Mr. Hanky]

It's not all instinct, though. Children are born with a poor sense of empathy, and have to be carefully taught (and sometimes punished for choosing selfishness over others' feelings/safety) in order to develop this sense of moral feeling toward others, to place the worth of others as equal to their own, in the sense of not doing harm. If you were a parent, you'd already know that. Our brains are sponges for social coding, from language to behavior, and continue to develop until into early adulthood (~25 years old), so a person who may naturally be able to feel empathy can still do great harm if they are not taught to be good, social/moral creatures.

This could start a chicken-or-the-egg diversion, but I doubt that empathy and socialization require any teaching, only experience and guidance for the avoidance of disastrous experience. Children aren't born social because they are born without fully-developed brains, but if raised in complete cultural isolation a normal adult would not be violent nor selfish, only unable to communicate in the culture which he then encounters as an adult. Then again, he probably wouldn't be sane from the long-term isolation, and such an experiment would be a cruel atrocity, so can't prove this. Anyway, I suggest that it's culture and etiquette, not empathy which requires teaching.