( CNN ) -- Last weekend , actor Jim Carrey tweeted that he has decided to withdraw his support for his movie `` Kick-Ass 2 '' due to its violent content . Carrey said he became uncomfortable with the violence in light of last year 's tragic Sandy Hook Elementary School shooting in Connecticut . People must make their own decisions about what media are appropriate for themselves and their family , and I respect Carrey 's choices . Yet , as someone who researches media violence , I worry that some will draw the wrong message from his position . Existing data do not link media violence with mass shootings or other societal violence . Debate continues in the general public and within academia , but the evidence just is n't there . The U.S. Secret Service and U.S. Department of Education , in a joint report in 2002 , found no evidence that school shooters consume more violent media than others . And although media probably have become more violent in recent decades , this period has also seen a massive decline in youth violence to 40-year lows , not an increase . Experimental evidence from social science has been mixed , and many of the studies are of poor quality . One scholarly paper that endorsed the `` harm '' view suggested religious books with violence such as the Bible would cause aggression just as much as a violent movie , something of which readers may wish to be aware . The U.S. Supreme Court rightfully rejected evidence such as this as unpersuasive when considering the Brown v. Entertainment Merchants Association violent video game case in 2011 . So why do beliefs about media violence persist ? Periods of moral panic tend to surround media . Media from penny dreadfuls ( trashy novels popular in the 19th century ) to comic books to music ( jazz , Elvis Presley , rock music , etc . ) to books such as Harry Potter have often been blamed for society 's ills . After events such as the Sandy Hook rampage , blaming the media can actually be reassuring . We construct the narrative that an individual such as Adam Lanza might never have committed his horrific crimes if not for the crucial influence of media . Such narratives give us a sense that the uncontrollable might be controlled . And to maintain them , we simply ignore cases that do n't fit them , such as a rash of violence in the months after Sandy Hook committed by elderly men with no discernible connection to violent media . This allows us to maintain an illusion of correlation where none exists . Professional advocacy groups such as the American Academy of Pediatrics share some of the blame in promoting unnecessary fears . As I detail in a recent report for the journal American Psychologist , previous statements by the group have been error-prone on even basic details , such as the number of studies , and simply omit those studies that conflict with alarmist messages . Unfortunately , people often take these policy statements too seriously , forgetting professional advocacy groups tend to benefit politically by identifying social crises their professions can help `` fix . '' The committees that write these statements have historically included scholars highly invested in a particular ideological view of media reviewing their own work and declaring it beyond debate ( a chance I 'd love to have with my own work one day ) . They should not be mistaken for careful , neutral , objective reviews . There are real dangers in focusing too much on media as the cause of violent crime . Speaking as a mental health provider , I 've seen no tangible improvement in the delivery of mental health services in the United States . It is a tragic , lost opportunity when we squabble over the old culture wars surrounding media , rendering media bashing as the new `` Twinkie defense '' for criminal defendants . Parents certainly deserve to have full information on ratings systems for media and existing controls . A recent Harris Poll suggested that individuals unfamiliar with the Entertainment Software Rating Board ratings systems for games , for instance , were those most concerned about video games -- suggesting that , as with previous moral panics , unfamiliarity breeds fear . Granted , media companies could work more -- in conjunction with schools perhaps -- to keep parents informed about the options available to them to restrict their children 's exposure to violent imagery ( and for the record I have no financial or personal ties to media industries ) . But parents also have the right to have a full understanding of the research , its inconsistencies and limitations , and this is something the research community could do better . Debates on media have been going on for more than 2,000 years and wo n't end in our lifetimes . But we must remember that the most powerful impact these debates have is in their ability to distract us from the real causes of violence : poverty , inequality and the lack of attention to mental health . The opinions expressed in this commentary are solely those of Christopher J. Ferguson .
Christopher Ferguson : Actor tweeted he wo n't support his new movie due to violence . Ferguson : Existing data do not link media violence with shootings or other violence . He says scholars use , at best , mixed study results to blame media for violent behavior . He says it distracts from roots of violence : poverty , inequality , poor mental health care .