operational definition of consensus

further three revisions (including the addition of a new author,Gollwitzer), before it was finally accepted for production.

pointed out a statistical flaw in the analysis of the data

The study, by Brad Bushman and Carlos Cruz at Ohio State University, and Mario Gollwitzer atPhilipps University Marburg, asked participants to complete an online survey asking them howmuch they agree with the statement “violent X can increase aggressive behaviour in children”,where X included a number of different types of media, ranging from comic books andliterature to movies and video games. They were also asked the extent to which they agreewith two other statements: one asking whether there is a causal relationship between exposureto violent media and aggression, and another asking whether media violence is a factor in reallife violence.

) 22 (8.2%) 42 (15.7%) 116 (43.4%) 70 (26.2%)Violent literature can increaseaggressive behavior inchildren.18 (13.6%) 24 (18.2%) 42 (31.8%) 38 (28.8%) 10 (7.6%)23 (9.6%) 58 (24.3%) 80 (33.5%

Bushman

Third, we did not pro-vide definitions for the various terms in thesurvey (e.g., aggression, violence, violentsports, violent literature, causal relationship).

Murray, 1984)

supporting catharsis theory

low base rates for rareevents

even additional reasons why peopledeny violent media effects

To argue against it [the linkbetween media violence and aggression] is likearguing against gravity” (Mifflin, 1999

The stance of a minority of researchers likeDr. Freedman, Dr. Olson, and Dr. Fergusonstand in stark contrast to the stance of publichealth and scientific organizations. For exam-ple, after reviewing the available evidence, sixpublic health organizations—American Acad-emy of Child and Adolescent Psychiatry, Amer-ican Academy of Pediatrics, American Acad-emy of Family Physicians, American MedicalAssociation, American Psychiatric Association,and American Psychological Association—endorsed a joint statement that concluded: “Theconclusion of the public health community,based on over 30 years of research, is thatviewing entertainment violence can lead to in-creases in aggressive attitudes, values and be-havior, particularly in children (“Joint State-ment,” 2000).

had publishedmore than 48 times more studies on the topic intop-tier journal

A review of thetwo briefs, side-by-side, reveals large differ-ences in expertise

(e.g., three em-ployees of video game companies)

basis of the First Amendment, not on thebasis of scientific evidence. Indeed, the Justicewho wrote the majority opinion (Scalia) admitsthat he did not even read the scientific studiesoffered to support the California law (Brown v.Entertainment Merchants Association, 2011)

Dr. Olson found that violent gamesactually decreased aggression in children withdepressive and attention deficit symptoms (Fer-guson & Olson, 2014)

Likewise, Dr. Christopher Ferguson said,“Violent video games are like peanut butter.They are harmless for the vast majority of kidsbut are harmful to a small minority with preex-

For example, Dr. Jonathan Freedman(2007) stated, “Those who propose that mediaviolence causes aggression have greatly over-stated the results of the research, and have gen-erally ignored findings that contradict theirviews.”

Op-Ed pieces published. In addition, videogame makers are fighting efforts to study thelink between exposure to video games and real-world violence (Levitz, 2013), much like theNational Rifle Association (NRA) fought ef-forts to study the link between guns and sui-cides, homicides, and accidents (Jamieson,2013).

This also happens in other scientific areas thatare potentially contentious. For example, on thetopic of climate change, more than 97% ofclimate scientists believe that climate-warmingtrends over the past century are very likely dueto human activities (Anderegg, Prall, Harold, &Schneider, 2010; Doran & Zimmerman, 2009),and most of the leading scientific organizationsin the world have issued public statements en-dorsing this position. But rather than interview-ing 97 climate scientists who believe in climatechange and 3 who do not, the media ofteninterview one scientist who believes in climatechange (e.g., Bill Nye “The Science Guy” orNeil deGrasse Tyson) and one scientist (or self-proclaimed experts) who does not. This may beone reason that public opinion about climatechange lags far behind the scientific evidence onclimate change

But science can cut through opinionto try to find the facts underneath. In addition,because most journalists are not trained as sci-entists, they may not be able to tell who theexperts are in a given field, and sometime

(a) journalists often report violentmedia research in a way that increases uncer-tainty about whether there is a link betweenviolent media and aggression; (b) media indus-tries have a vested interest in keeping the publicuncertain about the link between violent mediaand aggression, and actively promote this un-certainty; (c) a few media researchers repeat-edly claim that violent media do not increaseaggression; and (d) consumers of violent mediaare motivated to deny violent media effects

Parents might not be aware ofresearch showing that violent sports can in-crease aggression

, all participants agree that there is acausal effect of violent media on aggression, butthe strength of this agreement differs, with re-searchers expressing a small to moderate agree-ment, parents expressing a strong agreement,and pediatricians expressing a very strongagreement

pediatricians tend to exaggeratethese findings to some extent.

otably, pediatricians showthe highest level of agreement (average d 0.99, which corresponds to a large effect),whereas researchers and parents express a smallto moderate level of agreement (0.33  d 0.38)

(incontrast to 2 ) an unbiased estimator of the truepopulation effect size.

“Violent _____ canincrease aggressive behavior in children,” withnine different types of media inserted in theblank:

ailed attention check

(50% male; 4.2% NativeAmerican, 6.9% Asian American, 13.0% Afri-can American, 72.1% White, 3.8% more thanone race; 15.3% Hispanic; 18 to 61 years old,Mage  37.6, SD  9.6)

132 members of the Media Psy-chology and Technology Division of the Amer-ican Psychological Association (APA; 90.4%response rate)

Participants were 239 members from theMass Communication Division of InternationalCommunication Association (ICA; 21.9% re-sponse rate)

In addition, manyparents use the mass media as a virtual babysitter

tend to downplay any harmful effects of violentmedia

Exposure to violence in media, includ-ing TV, movies, music, and video games,represents a significant risk to the health ofchildren and adolescents” (American Academyof Pediatrics, 2009), we predicted similar, butstronger, responses from pediatricians thanfrom media researchers.

that violent media can increase aggressionin children, and that the effect is causal. Wepredicted the most consensus for movies andvideo games, which have become increasinglyviolent in recent years.

reviewed numerous times, and nearlyall have reached the same conclusion— exposureto media violence can increase aggression

Third, although extreme incidents ofviolence such as rampage shootings and mur-ders get the most media attention, such acts arerelatively rare. Most parents probably do notworry that exposure to violent media will turntheir child into a rampage shooter or a psycho-pathic killer. Rather, most parents are concernedabout the effects of violent media on less ex-treme forms of aggression, such as how theirchildren treat family members, friends, acquain-tances, and strangers.

Second, there is a relative dearth of researchstudies on the link between media violence ex-posure and real-world violence, whereas hun-dreds of studies (including numerous laboratoryexperiments) have been conducted on the linkbetween media violence exposure and aggres-sion.

First, researchers cannot conclusivelyprove that exposure to violent media “causes”real-world violence, because it is unethical forresearchers to conduct laboratory experimentsin which participants can commit violent acts

aggression that has as its goal extreme phys-ical harm, such as injury or death

Most researchersdefine human aggression as any behavior in-tended to harm another person who does notwant to be harmed (Bushman & Huesmann,2010)

It is useful to define the terms aggressionand violence, especially because lay peopleand researchers can use those terms differ-ently

Moreover, it is neverpossible to know for sure what caused a spe-cific individual to go on a shooting rampage

These unwarranted claims regarding therelationship between violent video games andviolent criminal behavior produces heated de-bates in the media

it is only natural

try, almost daily reports of victims, many of themchildren, in small towns and big cities all across Amer-ica—victims whose—much of the time, their only faultwas being in the wrong place at the wrong time. Wecan’t tolerate this anymore. These tragedies must end.And to end them, we must change. We will be told thatthe causes of such violence are complex, and that istrue. No single law—no set of laws can eliminate evilfrom the world, or prevent every senseless act of vio-lence in our society. But that can’t be an excuse forinaction. Surely, we can do better than this. If there iseven one step we can take to save another child, oranother parent, or another town, from the grief that hasvisited Tucson, and Aurora, and Oak Creek, and New-town, and communities from Columbine to Blacksburgbefore that—then surely we have an obligation to try.—President Barack Obama, Interfaith Prayer Vigil,

few vocal researchers claim there is a“debate” on this issue, the overwhelming majority of researchers believe that violentmedia increase aggression in children

media violence was a majorfactor in producing real-life violence: parents and pediatricians agreed that it was,media researchers did not agree.

All groups agreed that exposure to media violence can increase aggression inchildren (overall d  0.49, a medium-sized effect).

increase aggressionin children, whether that effect is causal, and whether it is a major factor in real-worldviolence.

anonymous online survey

The purpose of thisstudy was to test whether media researchers are in fact divided on this issue, and tocompare the opinions of researchers with those of pediatricians and parents.

There Is Broad Consensus: Media Researchers Agree ThatViolent Media Increase Aggression in Children, andPediatricians and Parents Concur