It is definitely the exception to the rule, I pretty much confirm that every day at school. I think its safe to say that only a small number of fourteen year olds would truly understand this game, but again, there are still exceptions. For example, Cloudstrife's statements are spot on from what I understand of human psychology, but that doesn't mean it applies to everyone, just the majority of people. I guess what I'm getting at is that I feel that I have a good understanding of this game and the concepts it presents, while my actual age is lower than the 16 mark. Perhaps you guys don't think so, and perhaps I don't truly understand the game, but from what I've seen I understand everything about it just as well as everybody else despite my age being lower.
It's a funny thing, but you don't know that you don't know until you learn what you didn't know. If you know what I mean.
When I was young I was fairly advanced (no, not a genius, I just grew up in a house full of academics). I was reading books like The Chronicles of Narnia when I was 4-5, and started reading authors like Tolstoy and Dostoyevsky when I was 11-12. At the time, I felt like I had a good command of the material and was pretty full of myself. I went back to books like
Crime and Punishment when I was in undergraduate school and was amazed by how much of it had gone completely over my head when I was in junior high. If I read them again in 10 years, I'll probably pick up on more stuff I missed. Now Fallout New Vegas isn't
War and Peace, but it's certainly not without its complexities.
Personally, I think a relatively nuanced game like New Vegas would be a good exercise in critical and moral thinking for 13+ year olds. But at that age it's not all that likely they'll fully comprehend the narrative nuances. And there is a big difference between the developmental stage of your average 13 year old and your average 8 year old, who almost certainly would not be able to process all (or even much) of it.
But adolescence is typically characterized by arrogance, ego centrism and obstinate willfulness, so you can't always count on a teen to even consider that they might not "get it".