It concludes that video games can hurt school work.
The study found that young boys who get a gaming system do not progress as quickly as quickly in school as boys who do not own video games.
The study says average reading and writing scores of young gamers do not go down, but they do not improve either.
Researchers say they need to study the effects over the long term to see if the findings hold up. The study is in the Journal of the Association for Psychological Science.