Yes, but this begs the question: What things influence kids to "commit the biological act"? I'm begging for the answer to that question.
I'm going to go way out on a limb here - no PhD research and all - but my guess is that hormones are what influence kids to have sex. Since I'm just making it all up, let me follow that with another guess. The parents who let their kids watch sludge like "Sex in the City" unsupervised are the same parents who let their kids have a friend of the opposite sex over unsupervised or visit with a "friend" whose parents are out of town or working late. It's not that sleazy TV leads to sex, but that both are results of neglectful parenting. BTW, I know that kids had sex before TV and even with attentive parents, but some parental neglect makes it a whole lot more likely.