Well, I think to know the answer to this question you would need to see what kids have really been doing all over the place. Every kid at my school is a virgin and there are at most 5 guys that got in to drugs or smoking and the likes. But of course, in other areas, the standards are different, and certain stuff is "the norm". Are kids really "growing up" faster than 10, 20, 30, 40, or 50 years ago? Or is it just that the things that are causing them to seem like they're growing up faster be different than 10, 20, 30, 40, or 50 years ago? This question can only be answered by someone with an amazing insight on a huge time span and a huge number of different areas.
Which nobody really has.