Hooray for feedback! Okay to clarify:

Quote Originally Posted by dragonprime View Post
One little nitpick though. How is it that they physical penalties keep building up but mental ones don't? A teenager is smarter than a juvenile.
Indeed, the teenager only gets a -1 penalty to mental stats, as opposed to the juvenile's -3 penalty. The mental stat penalties are also cumulative.

Quote Originally Posted by Charlie Kemek View Post
children wouldn't really get minuses to charisma or dex, more of the opposite.
Haa I knew I'd get pulled up for these two so allow me to explain. Concerning dexterity, a child may be small and lithe but they tend to lack the grace and finesse of their elders. As an example compare an adult ballet dancer to a child dancer; both could give enjoyable performances but whilst one moves fluidly over a complicated routine, the other is slower, a bit more ponderous in her actions and is probably trying hard to not fall over as she is still learning new skills and movements.
Kids are, at the end of the day, quite clumsy in comparison to their elders. Also, a lot of the dex-based skill checks rely on a degree of practise or training; I don't see kids being inherently better at lock picking or riding than adults.

For charisma, this again comes down to looking at the skills and realising that most of them boil down to influencing others. A lack of life experience or social technique often implies difficulty in getting their message across. It's quite common in media to depict children having their claims being ignored or rebuffed by parents or whoever.
Of course kids and teens can be quite willful in their approach, but given how martial DnD is, would you be taken seriously by a big, scary bunch of warriors when you haven't even reached manhood yet? In fantasy, the passing into manhood is a much greater event than RL; the right to bear arms; the expectation to provide for and defend the homestead; a valid opinion in the community; the decision to leave home (adventure!) etc. All of these are examples of benefits/responsibilities upon reaching adulthood.