Research conducted at the Iowa State University has concluded that violent games can desensitize players to real-life violence. According to Nicholas Carnagey, an ISU psychology instructor who served as a research assistant on the study, "it appears that individuals who play violent video games habituate or 'get used to' all the violence and eventually become physiologically numb to it."

The results, although discouraging, are rather obvious. Violent movies and television have been known to desensitize people to actual violence, and now we know video games to be no different. What must be differentiated, however, is one's desensitization to violence and one's ability to cause violence. This study in no way correlates to the causality of violence.
Conducted among 257 college students, the researchers made each participant play one of eight randomly assigned video games (four violent, four non-violent) and then had them watch a 10-minute videotape of real incidents of violence. Heart rate and galvanic skin response measurements were taken before and after the game playing and throughout the viewing of actual violence.

For the record, the violent games were Carmageddon, Duke Nukem, Mortal Kombat or Future Cop; the non-violent games were Glider Pro, 3D Pinball, 3D Munch Man and Tetra Madness.

The full report can be found here (.pdf file).

This article was originally published on Joystiq.