Question: A recent study for Planned Parenthood found that children who watched the most sex-saturated television were twice as likely to engage in sexual activity within the next year as those who reported a low level of television watching. Before concluding that sex on TV increases the likelihood of sexual activity, we should consider the possibility that it was their heightened interest in sex that caused them to choose that type of programming. Unfortunately, it is difficult to rule out such confounding variables in an observational study.