The report on what is a long-running debate, Screen Violence and Child Mental Health, is published by Young Minds, a children’s mental health charity. It concludes that “after 30 years of research, there is still no widely held consensus on whether or not violence on television and in videos causes violent behaviour.”

After the James Bulger killing, legislation was passed to restrict the availability of videos to young people. But this latest report rebuts any “simple policy response” and says that seeking direct causal links between television viewing and behaviour is “not realistic”.

Instead, the report argues that violence in children has varied and complicated roots, and that little, apart from tabloid headlines, is achieved by putting the burden of responsibility on isolated causes, such as watching violent videos.

After decades of claim and counter-claim about screen violence, the report, presented by Peter Wilson, director of Young Minds, now calls for fewer quick-fix solutions and a recognition of the complexity of the influences that shape a child’s personality.

He said there are not only very great differences in how individual children and families use and understand television, but also in how adults and children evaluate violence. As an example of how subjectively screen violence is defined, the report cites a previous generation’s investigation into the dangers of television, which showed Tarzan and Bonanza to groups of boys to see if these violent shows would provoke changes in their behaviour.

The report acknowledges that there have been cases where children have been adversely psychologically affected by what they view. These are not necessarily violent programmes, but can be benign images that accidentally trigger other insecurities, with examples in the report including a spoof documentary about ghosts, an advert and an item about Nostradamus. Young Minds calls for a more thorough gathering and analysis of such incidents.

Controlling what young people watch is becoming more and more difficult for parents, the report concludes. Videos can be readily imported, copied and viewed, and there is growing access to cable and satellite services carrying overseas channels which are far less censored than British broadcasters.

As such, the report says that it is “essential that all children are equipped with the critical skills needed to evaluate television, video and other media. All schools need to ensure that they afford primary importance to media education for all ages.”

* Top psychologists will today urge schools to help reduce the level of violence affecting children, citing it as a major component in the high incidence of emotional disturbance.

The Young Minds group is holding a major conference, sponsored by The TES, as the culmination of a year-long campaign to highlight the link between violence and mental trauma.

Peter Wilson, director of Young Minds, said: “All too often, violence is accepted as part and parcel of daily existence. Teachers in particular can do a lot to help. They can reduce bullying. They can spot those children who come into school looking tired, listless or upset.”

* Domestic violence causes long-term psychological damage to children, according to a new report from the National Children’s Home. In a survey of women caught up in domestic violence, the NCH researchers found that nearly a third of the mothers thought their children had become aggressive and resentful; nearly half said they had become withdrawn; and a third found their children developing problems at school.

Violence and Young Minds takes place today at the Friends Meeting House, Euston Road, London NW1, starting at 10am. Price Pounds 25.