There's more traffic in New Jersey, thus, they have to take better precautions when allowing people to drive. [/randomcompletelyuselessanswer]
If that was the case wouldn't you have to be like 30 to get you liscense in New York? Besides, I've been to Texas, and theres plenty of traffic there (they arn't far behind Los Angeles really).

Anyway, I got my permit when I was 16 and didn't get my liscense till 2 days after my 17th birthday...cause my parents are assholes. I'm 19 now (and still haven't had my first car -__-).