Parents who buy their children a video game system might want to be careful that all the fun doesn't interfere with their learning. A new study suggests owning a game system could hinder academic development, at least for young boys.

The results show that boys given a PlayStation II are slower to progress in their reading and writing skills and have more learning problems reported by their teachers than those not given a system.

The study is the first controlled trial to look at the effects of playing video games on learning in young boys. That is to say, the findings aren't based on survey data of kids' game habits, but instead on a specific group of children that were randomly assigned to receive a PlayStation or not, and followed up for a certain period of time.

However, the findings don't mean that parents should ditch their children's game systems.

"There's nothing evil about video games per say," said study researcher Robert Weis, a psychologist at Denison University in Ohio. "It's just that we need to monitor kids' usage of these games and to urge moderation in the amount that kids play these games."

While several studies have found an association between playing video games and poor academic performance, they don't reveal which direction the cause-effect arrow points. For instance, it could be that children who struggle academically turn to video games, because they enjoy it more than homework, Weis said.

Weis' new study involved 64 boys aged 6 to 9 who didn't currently own a video game system, but whose parents were thinking of buying one. The boys did not have previous learning or behavioral problems. The parents were told this was a study looking at child development, and they would get a video game system for participating. The scientists chose not to include girls, because they wanted to look at the effects of playing video games, and they were worried that girls might not play as much as boys would, according to Weis.

Half of the children were randomly chosen to receive the PlayStation right away, and half got it at the end of the four-month study period.

Not surprisingly, the children with the game system immediately spent more time playing video games than those in the control group, though the latter group did spend a little time playing video games, presumably at friends' houses.

Those with PlayStations also spent less time engaged in educational activities after school and showed less advancement in their reading and writing skills over time than the control group, according to tests taken by the kids. While the game-system owners didn't show significant behavioral problems, their teachers did report delays in learning academic skills, including writing and spelling.

The researchers think the learning problems result from the drop in after-school actives with educational value.

"The amount of time you have is zero sum, so if you spend your time playing video games you can't spend your time doing other things," Weis told LiveScience.

Playing video games might displace not only traditional academic activities, such as homework and reading, but ones that, while not strictly academic, could help them in school, such as discussing what they learned that day with their parents, or having parents read to them.

The findings do not suggest that video games can't have benefits. For instance, educational games may help learning, and previous studies have found that action games can improve vision. And they might have social benefits as well, since boys seem to bond while playing video games, Weis said.

More research is also needed to determine if these findings apply over the long-term, Weis said.

"It could be that the novelty of video games wears off after four or six or eight months, and they basically don't play as much as they did when they first got the system," he said.

Future studies will also need to see if the findings apply to girls, who generally spend less time playing video games than boys and chose ones with less violent content, Weis said.

The results were published in online Feb. 18 in the journal Psychological Science.

And in other news....water is wet. But really now, I could have told you this. Intense gaming, playing outside, sports...any of that is going to decrease scholastic abilities. The simple reason is like it said...if you're gaming, you're not doing your school work (or in my case...my work work).