I hope the TV was wearing protection

Journalists have a tendency to get over-excited when reporting the results of scientific research. So I wasn't surprised yesterday when I saw the following headline:

Study links sex on TV to teen pregnancy

Just when we thought we could keep our kids safe at home!

According to CNN:

Researchers at the nonprofit organization found that adolescents with a high level of exposure to television shows with sexual content are twice as likely to get pregnant or impregnate someone as those who saw fewer programs of this kind over a period of three years.

So is it time to turn off Gossip Girl? Perhaps not. Studies like this are good for showing correlations, or the fact that a relationship between two variables exists. They are less apt at proving what causes what. Consider this critique from the Tara Parker-Pope:

"...a closer look at the data shows the relationship between television, sexual content and teen pregnancies is complex. The same study, published today in Pediatrics, also found that teens who watch a lot of television in general are less likely to become pregnant. How can that be? The answer may be that kids who watch a lot of television obviously aren’t out dating and socializing with friends. So as unhealthy as it may be to spend hours in front of a screen, the behavior appears to be oddly protective against teen pregnancy...The link between television and teen pregnancy only shows up when a high proportion of the television shows watched by a teen are filled with sexual content."

So TV has two potential effects on teen sexual behavior. But it is also possible that there is some unobserved factor out there, which is actually at work. It is quite likely that teens who are more sexually active have a preference for more sexually explicit shows. This might make sense given the fact that while TV overall has gotten steamier, the overall teen pregnancy rate has gone down.

Either way, the authors conclude with a point that's hard to argue with:

“If the type of sexual portrayals that teens see on TV are the only messages they’re getting about sex, then they’re likely to approach sexual relationships in a way that might not be the healthiest way,” said Steven Martino, study co-author and a behavioral scientist at the RAND Corporation, the nonprofit health care research firm that conducted the study. “It’s important to talk to them about that and see how they’re reacting, and offer other perspectives to them about sex that they might not be getting on television.”