context: Bad behavior doesn't end when your child graduates from diapers -- or even from middle school. In fact, the teen years can bring some of the toughest discipline challenges parents have to face. Sulking, arguing, lying, and rebelling are just a few of the ways teens misbehave. There's a good explanation for these bad behaviors. As teens become more independent, they still lack the emotional maturity they need to make informed, thoughtful decisions. The parts of the brain that control decision making and impulse control haven't fully developed. The combination of autonomy and immaturity can lead to risky teen behaviors, like drinking, smoking, and having unprotected sex. You want your children to do the right things, but disciplining teens isn't easy. When they talk back, you can't just put them in a time-out like you did when they were toddlers. Effective parenting of teens requires smarter, stronger discipline strategies. The goal of discipline is to gain more control over your kids -- without being too controlling. Tweens and teens push boundaries to see how their parents will respond. It's important to establish clear rules, and to have consequences for breaking those rules. For example, the punishment for breaking curfew might be that your teen has to stay home the next weekend. You'll get less resistance if you involve your kids in designing their own consequences. Just don't forget that you still have the final say. So that there can be no misunderstandings, create a formal list of house rules, or type up a behavior contract that you and your teen sign. Post the list or contract on the fridge or in another central location where your kids won't be able to miss it. Examples of clear rules include: " Curfew is 8 p.m. on weekdays, 10 p.m. on weekends, and no going out until homework is finished." Spell out the consequences, too: " Anyone who breaks one of these rules loses television for a day." If your kids do fall out of line, all you have to do is point to the list. Teens are master negotiators and manipulators. They're adept at spotting any sign of parental weakness. When you waffle and give in to their pleas for leniency, they are going to expect the same response every time they misbehave or break a rule. Being consistent about teen discipline also means that both parents need to be on the same page. If one parent always says "yes" and the other always says "no," your teen is going to know exactly which parent to ask. While you're being firm, don't forget to also be fair and understanding. A little empathy goes a long way when disciplining teens. You want to be consistent, but not harsh. It's OK to give in about the small stuff once in a while, provided that it isn't something dangerous. For example, purple hair might not appeal to you, but it probably won't hurt your teen. Drug and alcohol use, on the other hand, are non-negotiable. If the rule is " No swearing in the house" and you curse like a sailor, you're giving your teen a free pass to do the same. The best way to encourage positive teen behaviors is to walk the talk yourself. An important part of parenting teenagers is to teach them how to make decisions. Kids need to learn that whatever choices they make -- good or bad -- have consequences. Sit down and talk about some of the dangerous and long-term consequences that risky behaviors can have, including drug abuse, pregnancy, smoking, and drunk driving. Know that no matter how well you prepare your kids, they're going to make some mistakes. The important thing is to show them how to learn from those mistakes. One of the best ways to prevent teen bad behavior is to know what your kids are up to. You don't need to spy on your teens or listen in on their phone conversations -- you just need to be an involved and interested parent. Ask what your kids are doing when they go out with friends. Know who they hang out with and where they go. Being an involved parent also means watching for any warning signs that your teen is in trouble. These signs include: skipping school, losing or gaining a lot of weight quickly, having trouble sleeping, spending more time alone, getting into trouble with the law, or talking about committing suicide. If you see any of these changes in your teen, enlist the help of a doctor or therapist right away. You might look back at your own teen years through rose-tinted glasses, but don't forget that this tumultuous time of life comes with a lot of stress. Teens are under an enormous amount of pressure to do well in school, excel at a lot of different activities, follow all the current fads, and fit in with their friends. Before you come down hard on your teen for bad behavior, try to understand what's driving it. Could there be trouble in school? Boyfriend or girlfriend problems? Bullying? Get your kids to open up to you about their problems by creating an environment of honesty and respect. Let them know that they can talk to you about anything. Even sensitive subjects like sex and drug use should not be off-limits. Let your teens know that you will always love and support them, no matter what they do.