Contrary to what you might have heard, parents-not friends-are the number one influencer of teens' behavior choices. Monitoring teen behavior (e.g., "Where are you going, and with whom? Here's what time you need to be back.") reduces behavioral risk among teens. Over 75% of teen pregnancies are unplanned, and the highest rate of new HIV infections occurs among young people aged 20 to 24. Research shows that when parents set rules for their kids and monitor them, sexual intercourse occurs later in life, and if teens happen to be sexual active, better parent communication influences behavior to reduce unwanted pregnancy into the future. Model good behavior, communicate, and keep eye on what your teens do.