Why are teens these days smoking, drinking, dating at a young age, being rude. etc..? I feel as if I am the only girl at my school who doesn't do any of these.

First of all teenagers tend to be 10x more dramatic than other age groups, because of their "phase" they go through where they want to be rebellious and whatnot.

Second, there could be a strong influence coming from their parents. Maybe they're just as bad as those kids, because they're the ones that taught them. It's either that, or peer pressure. And those kids affected by peer pressure are going to have an extremely rough time trying to think for themselves, which ofcourse leads to MANY different problems in the future. Some could be worse than others, like not being able to take the initiative to apply for the simplest of jobs because they couldn't think for themselves, they need someone to do it for them.

Unfortunately, since the beginning of time, every teenage group goes thru this to be "cool" and macho and all bada*s when in all reality it makes their peers and others sick. Now don't get me wrong, there are always exceptions to this and we are called Nerds which is fine by me.  

Many outgrow this with age but many don't and many move on at a young age because of it which is really sad but its life and life goes on and waits for the next generation of teens

Because parents don't know how to parent these days....
Or because their positive influences are zero to none. They take after each other and are influenced by what's around them.  Just remember, you become what you behold. If you are seeing, hearing, hanging around things that bring you down and cause harm, your tendencies will lean that way - your attitude will stink, and your outlook will be bleak. If you watch, and surround yourself with positive, uplifting influences, you will find yourself starting to act the same.

Going with what everyone else is doing is easy - it takes no effort. That's why so many people do it. It's going the opposite of everyone else that takes courage and intention.

Most teens do this stuff because they want to get attention. Especially girls, we want to look attractive and perfect, so we put makeup and all that stuff. As for guys, they do their own things. Another reason is because people are scared and they don't want to be made fun of, they think it's cool to do harmful things. But they don't realize that these things leads them into danger if they're not careful.

Satan convinces them that it will make them look cool, seem mature, fit in, or stand out.  He also convinces them that rumors of their health "benefits" are true.  Teenagers don't generally think; normally, they feel.  The connections between the emotional part and the rational part of their brain won't be fully developed until they are around 25 years old.

I hate to break it to you, but this is what teenagers have been doing for generations. They are challenging their boundaries. Stay true to yourself and don't worry about what others do.

It's tough being a kid these days, most need a good hobby to keep them busy , and out of trouble. Parents should encourage this more, and take part in their child's activities.