Actually you got me thinking about what movies I saw when I was 7, and only Disney came to mind. But my mom, who raised me, in all other aspects your normal, non-controversial, basic mom, decided I didn't need a filter shortly after that. This resulted in me seeing "mature" movies from 8-years-of-age onwards, a decision that I absolutely loved. So my early film education went something like this
8-years-old: From Here to Eternity; Stalag 17; Shane
9-years-old: On the Waterfront; Sabrina; Rear Window; A Star Is Born (Garland); Vera Cruz; Desiree
10-years-old: Rebel without a Cause; The Man with the Golden Arm (still my favourite soundtrack music); The Night of the Hunter; East of Eden (the only one that bored me); The Blackboard Jungle; The Bridges of Toko-Ri; The Desperate Hours; Love Is a Many-Splendored Thing
11-years-old: Invasion of the Body Snatchers (scared me but in a fun way); Giant; Moby Dick
(thought Peck was miscast--so I am already developing into a little critic); The Bad Seed; The Harder They Fall
12-Years-old: 3:10 to Yuma; Cat on a Hot Tin Roof; An Affair to Remember; 12 Angry Men; The Bridge on the River Kwai; Witness for the Prosecution; Night of the Demon (Tournier) (I thought it was brilliant).
My point is, some kids can handle adult fare with aplomb. Even now, looking back, I don't remember feeling the least bit surprised about being allowed to see all these movies so young. They just seemed, with rare exceptions like East of Eden and Giant, like interesting movies, my kind of movies. No big deal whatsoever In fact, they, and the additional Disney and Hitchcock stuff, whetted a life-long interest in cinema in all likelihood. It may seem weird to contemporary parenting, but for me, it was just normal. Given the level of carnage, core, questionable language, and violence in movies now, I doubt a contemporary version of my mother would be so sanguine anymore. But I am grateful that she was at the time.