I agree its not a sharp example, there are lots of interacting effects and factors. But to me at least the statistics seem rather overwhelming. Social structure and rules and enforcement seem more tailored to mop up aberrations rather than constrain "normal" behavior. There is probably social studies of toddlers etc that analyze this question when conforming behaviors are less developed. I don't recall reading something that proves it is only learned cultural norms that "pacify" us.
In different places and times there were different thresholds on the level of violence acceptable to society.
We should be careful to not project our current norms on the entire history of humanity.
A quote from A Distant Mirror The Calamitous 14th Century by Barbara Tuchman:
In village games, players with hands tied behind them competed to
kill a cat nailed to a post by battering it to death with their heads, at
the risk of cheeks ripped open or eyes scratched out by the frantic
animal’s claws. Trumpets enhanced the excitement. Or a pig enclosed
in a wide pen was chased by men with clubs to the laughter of
spectators as he ran squealing from the blows until beaten lifeless
and another one:
The citizens of Mons bought a
condemned criminal from a neighboring town so that they should
have the pleasure of seeing him quartered.
The criminal was a) condemned, so organized state violence and b) brought over by the entire village, so a group of people. Not an individual outburst of violence, then.
The group of people trying to head-butt the chicken to death are playing a sport. Often enough to at some time add trumpets to it.
