Yes, all little children are at risk for trauma from big screen violence. No point in asking parents who have brought the first grader to a midnight movie, because people like that obviously haven’t thought about it and made a decision that their six year old would like it. They haven’t thought about their child at all, he’s like a bag of groceries or an umbrella that they just happen to have with them.
i think it all depends... my children were raised with classical literature... none of the ooey gooey Disney versions... they handled "scary" really well... we didn't schlep them like luggage... we were and are still thoughtful about what they are exposed to...
but you're right... some kids don't handle scary well.. i have friends whose kids could not watch the Wizard of Oz nor A Christmas Carol...