Historian Joel F. Harrington, whose most recent book concerns the inner life of a prolific executioner in 16th-century Nuremberg, suggests that civilization hasn’t become less violent; the nature of violence has changed:
To argue our own (or any) society is more or less violent than in the past misses the point at an even more fundamental level: Violence is broader and deeper than just intentional killings or physical assaults. Perhaps because I commute on a near daily basis between the sixteenth and twenty-first centuries, I see in both eras an intuitive understanding that human violence is much more pervasive and malleable than mere homicide statistics suggest.
Consider self-harm:
Perhaps the most obvious indictment of modern internalized violence is the global spike in suicides during the past 40 years, particularly among the young. According to the World Health Organization, self-killing today accounts for four times as many intentional fatalities as war or other state violence, and 15 percent more than homicide — the inverse of [16th-century] Europe.
Previous Dish on the history of violence here.