Playing violent video games, even for only 20 minutes, desensitizes people to real-world violence, new research contends.
"We found that the subjects who played violent video games for 20 minutes had lower physiologic responses when they watched videos of real-life violence," said Nicholas Carnagey, who conducted the research while a psychology instructor at Iowa State University in Ames.
He explained that these lowered physical responses meant the person felt less emotional upset when viewing real-life brutality.
Prior studies have reported a correlation between exposure to violent video games and desensitization to real violence. But Carnagey's team say theirs is the first to expose subjects to video games and then measure their physiologic reactions to real-life violence through heart rate and galvanic skin response, which evaluates perspiration.
As heart rate and perspiration increase, so does emotional arousal, said Carnagey, who is now a professor of psychology at the University of Michigan and the Vrije Universiteit in Amsterdam.
Released online ahead of print in the Journal of Experimental Social Psychology, the study included 257 college students (124 men and 133 women) who were tested before and after playing violent or non-violent video games for 20 minutes. Violent games included Carmageddon, Duke Nukem, Mortal Kombat and Future Cop. Non-violent games included Glider Pro, 3D Pinball, 3D Munch Man and Tetra Madness.
All of the participants had similar heart rates and other signs of arousal before exposure to real-life violence, which included videotaped shootings, prison fights and police confrontations.
"The only time we saw physiologic differences [among participants] was while they were watching real-life violence," Carnagey said.
The people who played violent video games for 20 minutes had lower galvanic skin responses (lower perspiration) and heart rates while watching the real-life footage. "A lot of other studies on exposure to violent video games indicated that we would find this [desensitization], but it surprised us that only 20 minutes of exposure was enough to show this effect," Carnagey said.
Translated to the real world, these signs of lower emotional upset may mean a person is more desensitized to violence. He or she may also be less able to identify violence and less likely to help victims of violence, Carnagey explained.