What makes humans special is not our occasional propensity to kill strangers when we think we can do so safely. Our unique capacity is our skill at engineering peace. Within societies of hunter-gatherers (though only rarely between them), neighboring groups use peacemaking ceremonies to ensure that most of their interactions are friendly. In state-level societies, the state works to maintain a monopoly on violence. Though easily misused in the service of those who govern, the effect is benign when used to quell violence among the governed.

Under everyday conditions, humans are a delightfully peaceful and friendly species. But when tensions mount between groups of ordinary people or in the mind of an unstable individual, emotion can lead to deadly events. There but for the grace of fortune, circumstance and effective social institutions go you and I. Instead of constructing a feel-good fantasy about the innate goodness of most people and all animals, we should strive to better understand ourselves, the good parts along with the bad.

The feel-good crowd tends to look at the connection between bad parenting and crime as a process of changing an innately good person into a bad one.  A more realistic assessment is that people are basically selfish beasts who need to be civilized, and bad parenting is a failure to civilize.  As parenting research showed long ago, permissive parenting is just as bad as authoritarian parenting. For the larger society as well, excessive permissiveness based on a naive view of human nature is folly, and a dangerous folly.