I know that you are aware that the history of this country contains an ever expanding frontier wherein each man, each family, each small band of folks had to tend to their own safety. They had to protect themselves from the bad guys as well as provide their own food and necessities.
So, yes, that independence which was contained within necessity is part of the American ethos.
Of course, Canada was a very similar settler demographic,
and also began as a frontier country...
Murder Rate: DEFINITION: Homicide rate per year per 100,000 inhabitants in various countries.
Jamaica: 60 murders / 100,000
USA: 5 murders / 100,000
CAN: 2 murders / 100,000
http://www.nationmaster.com/country-info/stats/Crime/Murder-rate
Well the facts speak for themselves. It is possible to have a civilized, modern society that's not awash with police brutality or firearms. I just doubt it's possible here. The love, fascination, and obsession with firearms is simply too deeply ingrained.
I'm not sure, but this might be related to the difference
for instance between Canada and the USA:
https://www.youtube.com/watch?v=pJsiAz9qCmM
When Canadians are essentially "anonymous members of the public",
they seem to self-identify differently than Americans.
Its as if Americans feel they must "uphold" or enforce the
Protestant Work Ethic of the previous century,
even when America is now a "Post-Christian"/ Anti-Christian culture.