American Beauty is one of my favorite films to date. I first saw the film when I was 14, not because my parents had prohibited it but because no one had ever thought to bring it up as a movie I might want to see. I watched it with my mother, father and younger brother present and we all enjoyed the film.
In terms of style, script and message, it is powerful and thought-provoking. But the many awards that it has should tell you that.
My brother was about 11 when he watched this movie and, honestly, he wasn't interested at all. He likes movies where things get blown up. But, even at 11 he could understand the movie and accept it- it just wasn't what he likes. My brother is, admittedly, quite mature for his age, which is why I wouldn't recommend it for an 11 year old, but instead a 13+ age range.
Of course, some children are more mature and responsible than others but on average I believe almost anyone aged 13 and up is mature enough to understand, appreciate and process this movie. Of course, they may have questions and I would advise any parent to sit down and answer them as, at times, the movie can be confronting.
At the age of about 13 children start to understand that the world doesn't contain pixies, the tooth fairy or Santa Claus. And, at times, the world can be quite ugly in some aspects. But there are also good things as well and I believe it is films like this that highlight the good, the bad and the ugly.
I believe parents and adult often regard children, particularly teenagers, as naive and still not understand how the world works or believe we aren't ready for the hard truths of life. And, I admit, we don't know everything but it's around this time when we start noticing things and may know and understand more than you think.
American Beauty is an amazing film and currently my 3rd favourite.