The comment regarding Grossman in this post is echoed by too many people I know who have valid, cross-referenced body-stacking credentials for me to ignore it.
I don't know what video games Rwandan teens were playing to get them over their reluctance to chop up fellow humans with machetes, or what movies Cain watched to help him overcome his inborn resistance to killing Abel...and neither does Grossman. Humans have been easily...almost casually...killing other humans for as long as there have been other humans to kill. Lose your illusions.
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