The beeb, with characteristic false self-deprecation, seems to be quite happy to promulgate the oldest urban myth around...ie: that TV viewing screws up your child. The version of this rubbish is updated to fit the zeitgeist. Seeing as bullying is the issue of the moment, the current theme is run out as "TV viewing will turn your child into a bully".
Spiked seems to have the measure of this issue.
Yep...this sort of research is rubbish. It is entirely pseudo-scientific. Not one of the so-called facts is falsifiable. Every single possible explanation cannot be tested against the data, since all other possible explanations could also fit. ie: children who watch more telly may bully more, (if that is indeed the case), because they watch telly, or because they eat more junk, or because they don't get the moral information that they need, or because dad tries to get them off the telly all the time and they build up a lurking resentment which they then let loose on some unsuspecting victim or because they are being bullied so badly at school that TV and bullying provide them with the only forms of escape and retribution, etc, etc.
These studies are a fine example of foul play. What happens is that someone with an entrenched, and therefore beyond rational criticism, idea of the high principle of self-denial, sets out to prove his hypothesis with an investigation that cannot, in principle, be categorised as science, but which will pass for such with quite a few of us saps.