The results of research conducted by Morgan Tear and Mark Nielsen from the University of Queensland (Australia) concludes that playing violent video games does not diminish prosocial behavior (in other words, it doesn't make participants anti-social as some research has claimed). The results of the research was recently published in the journal PLOS ONE.
Three experiments explored the effects of playing different types of games - contemporary violent, non-violent, and prosocial video games - on prosocial behavior, as measured by a "pen-drop task." Games played included Grand Theft Auto IV, World of Zoo, Portal, Call of Duty: Black Ops, and some classic game titles. At the end of the three experiments researchers came to the following conclusion:
Each participant played one of four video games for 20 minutes. At the end of the test, a researcher pretended to drop some pens to see how many players would help pick them up. No matter what game participants play, around 40-60 percent of them helped pick up pens at the end of the study. In a second experiment, they found that participants were more likely to help out when pens were dropped half-way through the experiment (75 percent).
"We failed to find evidence that playing video games affects prosocial behavior. Research on the effects of video game play is of significant public interest," the researchers wrote. "It is therefore important that speculation be rigorously tested and findings replicated. Here we fail to substantiate conjecture that playing contemporary violent video games will lead to diminished prosocial behavior."
You can check out the full research paper on PLOS ONE.