Violent videogames don’t turn children into real-life murders, but they may prompt the odd harmless scuffle in the playground, two US boffins have claimed.

Lawrence Kutner and Cheryl Olson, directors of the Harvard Medical School Center for Mental Health and Media, recieved $1.5m (£770,000/€970,000) of US Department of Justice money to study on the effects of videogames on kids' behaviour.

Over a two-year period the study, which the pair have written a book* about, questioned 1200 children between the ages of 11 and 14 about their attitudes towards violence and videogames. The results found that playing videogames is a sociable activity for kids and that - unsurprisingly - nearly all of them do it.

However, the research found a possible link between aggressive behaviour and mature rated titles – a rating that the US games industry's voluntary rating scheme suggesrs shouldn’t be played by anyone below the age of 17.

Of the 1200 kids questioned, around 51 per cent of boys who had played a mature-rated videogame in the past year had also been in a fight during the same period. Only 28 per cent of those who hadn’t played such games had been in a scuffle.

Those two percentages fall, respectively, 40 per cent and 14 per cent, when the researchers tallied up the results of their conversations with girls.

The researchers suggest that kids with a tendency toward violence probably shouldn't play adult-oriented video games, but for the rest, the negative impacts are marginal and the benefits - primarily social - surprisingly strong.

The duo’s research isn’t likely to change the minds of many parents and anti-videogame violence campaigners, such as British Labour MP Keith Vaz, who still maintain that such games can be damaging to society.

*Grand Theft Childhood: The Surprising Truth about Violent Video Games and What Parents Can Do