State of Nature

Life among our primate relatives is more nasty, brutish, and short than life among any human society:

Can chimpanzee skirmishes tell people anything about their own violent tendencies? One lesson, which may surprise cynics, is that humans are more peaceful than chimps. The rate of killing Dr Mitani reports is between one-and-a-half and five times that seen in human agricultural societies—and between five and 17 times higher than attrition due to warfare among hunter-gatherers, who could have less need to defend territory than farmers. 

from this article

Studies like this have been accumulating for years.  And yet people still believe the myth of an idyllic life before civilization.  People like Rousseau were simply wrong, about almost everything.  Life without economic growth is a horrible Mathusian grind that leads to all kinds of bad behaviors.