From time to time, one reads something about past centuries to remind one that people were even more violent in the past, restrained only by their lack of technology. There is a term, "pacification of the past", for the usual unwillingness of history books or movies or etc. to show just how cruel most people (male, female, adult, child) were, for no reason other than sport.
If they could time travel forward to the 21st century, they would probably find us to be oddly bloodless and placid. I wonder what we will look like to 22nd or 23rd century historians.