I don't honestly remember being shocked - and certainly not damaged. I was vaguely bored during most of it... and mildly (and morbidly) fascinated by the sexual violence. I think I found the revelation at the end of CHINATOWN (which I saw a bout a year later, on a "return to the cinemas"...
I honestly couldn't say what was going through my aunt's mind. I know my mother still expresses embarrassment that she allowed my brother and me to sit through it. I don't remember too much about it, other than the rape scene with the mentally challenged guy.
I do know that we set out for HARRY...
At age 13, this was, rather unaccountably, the first R rated movie I ever saw... I still tease my mother about how she wouldn't let me see The Exorcist, but let my aunt talk us into seeing this piece of garbage!