American Moral Shock-Ability and Film

Moral shock generations in the U.S. can be divided into:

1. The Psycho Generation (September 1960 on): shocking for its suspenseful horror when first released in 1960, it's almost humorous now (the blood going down the drain was really chocolate syrup). Still, back then, the whole country couldn't sleep for weeks--or take a shower, for that matter.
2. The Graduate Generation (December 1967 on): nowadays it may seem pretty tame, but his one completely upended social mores of the time with its adulterous theme. 
3. The Godfather Generation (March 1972 on): seemingly outrageous violence for the time, especially domestic, the horse head scene was all the country talked about for months, now high school kids laugh at the depictions. This was back when we could still be morally outraged.
4. The Pulp Fiction Generation (October 1994 on): not only could the nation no longer be morally outraged, director/writer Quentin Tarantino encouraged the audience to laugh at the fact that a moral line between acceptable and unacceptable no longer existed. 

The inclusion of Psycho here suggests it's more about shock-ability than just moral outrage-ability, though stabbing a girl in the shower would seem to cross some line or another (as would stuffing your mother).