The pornography of violence in WWF wrestling and video images have to be damaging. The problem is that such imagery is so prevalent that many parents (me included, sometimes) are becoming desensitised and adopting a laissez-faire approach. Is it really realistic to turn off the TV completely, or to censor Buffy the Vampire Slayer when all your child's friends are watching it too?

So to help you steel your courage (and to feel a little less guilty), here are the results of yet another study: researchers at Stanford University have found that aggressive behaviour in eight-, nine- and 10-year-old children decreases when television and videotape viewing and use of video games are reduced. Not cut out completely - just reduced.

Two schools were chosen: in one, 18 classroom lessons were devised, designed to encourage children to reduce the time they spent in certain targeted activities, including TV viewing and violent video games. In the other school - which was used as a control group - children's activities were monitored but there was no intervention.

In the intervention school, the children were given a 10day challenge to participate in none of the targeted activities, followed by an encouragement to follow a seven-hour-per-week "budget" for activities containing violent imagery.

Compared with the control group, the children in the intervention group had statistically significant decreases in peer ratings of aggression and teachers observed less verbal aggression on the playground. Parents reported less aggressive behaviour at home, and also noted a marked change in children's self-reported perceptions of the world as a "mean and scary" place.

The concept of the "10-day challenge" and the "seven-hour budget" seem like great ideas which Irish schools could easily copy. I don't know how long-lasting the effects would be, but it would at least get children - and parents - thinking more about how much violence their children are witnessing and, through video games, participating in.

The study was reported in the Archives of Pediatrics and Adolescent Medicine