The Testimony of Joanne Cantor PhD Professor Emirita University of Wisconsin-Madison before the US Senate Commerce Committee in 2003 provides an overview of the research available.

"We now know a lot about the effects of media violence. Study after study has found that children often behave more violently after watching media violence. The violence they engage in ranges from trivial aggressive play to injurious behavior with serious medical consequences. Children also show higher levels of hostility after viewing violence, and the effects of this hostility range from being in a nasty mood to an increased tendency to interpret a neutral comment or action as an attack. In addition, children can be desensitized by media violence, becoming less distressed by real violence and less likely to sympathize with victims. Finally, media violence makes children fearful, and these effects range from a general sense that the world is dangerous, to full-blown anxieties, nightmares, sleep disturbances, and other trauma symptoms.

The evidence about these effects of media violence has accumulated over the last few decades. Meta-analyses, which statistically combine all the findings in a particular area, demonstrate that there is a consensus on the negative effects of media violence. They also show that the effects are strong – stronger than the well-known relationship between children’s exposure to lead and low I.Q. scores, for example. These effects cannot be ignored as inconclusive or inconsequential.

Even more alarming, recent research confirms that these effects are long lasting. A study from the University of Michigan shows that TV viewing between the ages of 6 and 10 predicts antisocial behavior as a young adult. In this study, both males and females who were heavy TV-violence viewers as children were significantly more likely to engage in serious physical aggression and criminal behavior later in life; in addition, the heavy violence viewers were twice as likely as the others to engage in spousal abuse when they became adults. This analysis controlled for other potential contributors to antisocial behavior, including socioeconomic status and parenting practices."

Please check the reference list to see a small sample of the research data available on the internet. Some media training resources are also listed for convenience.