It is bullshit. The group that performed this study has already done this before and those conclusions were practically laughed out of academia 2 years ago. This looks like nothing more than an attempt to save face with a new study that is just as flawed in both its methodology and conclusions as the last one.

There are more factors to it than that. It really is sometimes simply a matter of genetics and/or psychology. Some people are just violent and unstable. They were as kids. They are as adults. They sometimes have the most loving parents in the world and no problems in their lives and it makes no difference.
Games might act as a catalyst to these people. But then so have a great many religious texts. Not least of all the Bible and Koran. Yet there are few of these 'moral majority' types who want those banned (some German lawyers did try and get the Bible banned for violent content. But mostly it's unheard of).

It's not that simple. http://news.bbc.co.uk/newsbeat/hi/technology/newsid_7540000/7540623.stm
That cab driver would be alive if it was not for GTA4. The punk was playing the game in an arcade, ran out of money, went out and murdered the cabbie.

Wait...there's still ARCADES in the world ....today?!?!?

I'm sorry for being from Iowa.

*pats head*

*fixed
Nobody with at least half a functioning brain would do that. As stated above, psychos could be influenced by anything. We're not about to consider banning everything, are we?

Let's check which mass murderer-leaders played chess, Hitlers, Stalins, and such.;P
No, the cab driver would be alive, if the kid wasn't a mental case. If we take Your statement here as a proof, we should ban religion, because there were a few nut jobs claiming Jesus told them to kill people. Was Jesus the reason? No.
[edit]
Damn, Navagon beat me to it! I'LL KILL YOU! LET ME JUST GET MY CHAINSAW! AARRGH!
[/edit]

I've always thought the other way around;violent video game makes most people fearful or more cautious. I mean after seeing a guy being decapitated with an axe, you'd be more careful handling axes, no? Besides mature entertainment for healthy minds is just that, entertainment or...guilty pleasures like:
bad horror movies that some people seem to really, really like
or "gorehounds"
or gossip shows
or
WARNING INCOMING RAGE:
<rage>
"people who only watch telenovelas no matter how ridicuosly dumb, childish, SUPERCALIFRAGILISTICEXPIALIDOCIOUS ficticious the plot and the setting and the horrible over the top freaking acting and the events(GOD SAID THE DUMB CHARACTER SHOULD BECOME HER HUSBAND,what the fffffffffffffffffffffff!) are"
</rage>

Do videogames promote violence? Maybe. But if so, at least they promote CREATIVE violence. Think about it.
Which is cooler? Stabbing someone in the chest with a knife you pulled out of a kitchen drawer? Or driving a truck full of C4 OUT OF THE BACK OF AN AIRPLANE towards your target only to leap out of the driver's side window mere moments before impact whilst firing away with a shotgun in slow motion in the instant before the truck crashes and explodes in massive fireball that will destroy the entire block?
On a more serious note, I would contend that American culture in general tends to promote violence to the point of idolizing it. The taboo against hurting people is not very strong here, but there is far more in our media and in our traditions to enable thoughts of destruction than a few decades of games. Elements of jingoism and xenophobia are taught to every child, whether they are given copies of Manhunt or not.

An immediate red flag on the study is that it's actually a meta-analysis: basically the guy took a whole bunch of other studies people have done then compiled the results. These kinds of meta-studies are rarely any more accurate or conclusive than any individual study, and also offer many opportunities to introduce errors in methodology on top of any problems with the original studies. In short, nothing much to see here.

That is by far one of the major driving forces behind violence. More so psychology (whether it be illness, trauma brought on by a catalystic event, the environment around the person and so on).
Thing is, these sorts of people are more than willing to be narrow sighted.
Games may promote violence as a solution to young, and particularly impressionable minds. Having said that, let's take a look around us. Violence readily available on TV, the Teenage Mutant Ninja Turtles back in the 90's. No one cared about the violence, however, there were those same impressionable minds going around thinking that violence is the first and best solution. That's but one example, there are a lot of TV programs that are "innocent", yet promote violence as the solution.
The TV and movie industry is full of violence, among other things. While there are regulations in most countries, it's usually up to management on how effectively it is enforced.
As far as TV goes, well.. Say there's a murder mystery that the TV network is aching to use as filler, but it was such a bomb (straight to VHS/DVD sort of thing) that they don't consider taking up prime real estate, thus it's shown (especially around here) during midday.
The news isn't regulated, and sometimes you do end up seeing very unrelenting acts of violence that were caught on tape. Sure, kids don't care about the news. But how many parents are exceptionally mindful to usher their kids out of the room when they want to be "informed"?
Literature, whether it's young adult fiction or comic books. There is violence present a lot of the time, because as we all know, violence equals action.
Music.
LIFE.
How many fights occur in the school yard? And in some cases, how many of them turn into loss of life?
Violence is all around us, we're subjected to it on a daily basis and are rather blase about it all. "Oh my gosh, how terrible.. Did I floss this morning?"
But sure, let's focus on videogames as the ultimate evil in this world, rather than focusing on a lack of personal accountability.
Let's all blame the other guy, because we are above what is wrong.
"Children are educated by what the grown-up is and not by his talk. " - Carl Gustav Jung

I never understood why professionals would want to make up crap to support their absurd claims. Isn't the idea of these kind of tests to uncover the truth? Wouldn't they achieve the same sort recognition for either proving or disproving these ideas correctly? Do certain, messed-up scientists get a hard-on for lying to people and seeing them eat it all up because it came from a scientist? Does that give them a power high?

I think Jack Thompson is backing these studies.