I can say that age CAN determine expectations of what people have for a certain age to be mature. For example, I don't really think under 10 would be that mature. Talking of drinking, driving etc, age restrictions, I think are neccessary to have an age restriction, as most people under the age of driving/drinking etc, do not have the responsibility. Do not mistake me though, this does not apply to everyone.
Also, I think maturity has a lot to do how your parents bought you up. I've seen really, really strict parents, you'd expect their child to be, like, REALLY mature, but in fact, I believe strict parenting just makes the child WANT to be immature sometimes. I believe freelance parenting can lead to a mature child, just as long as your child does not go too far with matters (Such as drugs etc, if I were to have a child and my child went into drugs, I'd step in.)
Also, I think maturity has a lot to do how your parents bought you up. I've seen really, really strict parents, you'd expect their child to be, like, REALLY mature, but in fact, I believe strict parenting just makes the child WANT to be immature sometimes. I believe freelance parenting can lead to a mature child, just as long as your child does not go too far with matters (Such as drugs etc, if I were to have a child and my child went into drugs, I'd step in.)