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The study of violence in mass media analyzes the degree of correlation between themes of violence in media sources (particularly violence in video games, television and movies) with real-world aggression and violence over time. Many social scientists support the correlation. However, some scholars argue that media research has methodological problems and that findings are exaggerated.(Ferguson & Kilburn, 2009; Freedman, 2002; Pinker 2002; Savage, 2004)
Complaints about the possible deleterious effects of mass media appear throughout history; even Plato was concerned about the effects of plays on youth. Various media/genres, including dime novels, comic books, jazz, rock and roll, role playing/computer games, television, movies, internet (by computer or cell phone) and many others have attracted speculation that consumers of such media may become more aggressive, rebellious or immoral. This has led some scholars to conclude statements made by some researchers merely fit into a cycle of media-based moral panics (e.g. Gauntlett, 1995; Trend, 2007; Kutner & Olson, 2008). The advent of television prompted research into the effects of this new medium in the 1960s. Much of this research has been guided by social learning theory developed by Albert Bandura. Social learning theory suggests that one way in which human beings learn is by the process of modeling.
Media effects theories in modern times originated with Bandura's social learning theory, which suggests that children may learn aggression from viewing others. Modeling of behavior was observed in Bandura's Bobo Doll experiments. Bandura showed children a video of a model beating up a Bobo doll and then put the children in a room with a Bobo doll to see if he/she would imitate the behavior previously seen on the video.
The findings of this experiment suggest that children tended to model the behavior they witnessed in the video. This has been often taken to imply that children may imitate aggressive behaviors witnessed in media. However, Bandura's experiments have been criticized (e.g. Gauntlett, 1995) on several grounds. First, it is difficult to generalize from aggression toward a bo-bo doll (which is intended to be hit) to person-on-person violence. Secondly, it may be possible that the children were motivated simply to please the experimenter rather than to be aggressive. In other words, the children may have viewed the videos as instructions, rather than incentives to feel more aggressive. Third, in a latter study (1965) Bandura included a condition in which the adult model was punished for hitting the bo-bo doll by himself being physically punished. Specifically the adult was pushed down in the video by the experimenter and hit with a newspaper while being berated. This actual person-on-person violence actually decreased aggressive acts in the children, probably due to vicarious reinforcement. Nonetheless these last results indicate that even young children don't automatically imitate aggression, but rather consider the context of aggression.
Given that some scholars estimate that children's viewing of violence in media is quite common, concerns about media often follow social learning theoretical approaches.
Social Cognitive Theory
Social cognitive theories build upon social learning theory, but suggest that aggression may be activated by learning and priming aggressive scripts. Desensitization and arousal/excitation are also included in latter social cognitive theories. The concept of desensitization has particularly gotten much interest from the scholarly community and general public. It is theorized that with repeated exposure to media violence, a psychological saturation or emotional adjustment takes place such that initial levels of anxiety and disgust diminish or weaken. For example in one recent study, a sample of college students were assigned at random to play either a violent or non-violent video game for 20 minutes. They were then asked to watch a 10 minute video of real life violence. The students who had played the violent video games were observed to be significantly less affected by a simulated aggressive act than those who didn't play the violent video games. However the degree to which the simulation was "believable" to the participants, or to which the participants may have responded to "demand characteristics" is unclear (see criticisms below). Nonetheless, social cognitive theory was arguably the most dominant paradigm of media violence effects for many years, although it has come under recent criticism (e.g. Freedman, 2002; Savage, 2004). Recent scholarship has suggested that social cognitive theories of aggression are outdated and should be retired.
One alternative theory is the Catalyst Model (Ferguson et al., 2008) which has been proposed to explain the etiology of violence. The Catalyst Model is a new theory and has not been tested extensively. According to the Catalyst Model, violence arises from a combination of genetic and early social influences (family and peers in particular). According to this model, media violence is explicitly considered a weak causal influence. Specific violent acts are "catalyzed" by stressful environment circumstances, with less stress required to catalyze violence in individuals with greater violence predisposition. A challenge for this theory will be to demonstrate how the exposure to violent media sources cannot be considered a significant early social influence although some early work has supported this view (e.g. Ferguson et al., 2008).
Moral Panic Theory
A final theory relevant to this area is the moral panic. Elucidated largely by David Gauntlett, this theory postulates that concerns about new media are historical and cyclical. In this view, a society forms a predetermined negative belief about a new medium — typically not used by the elder and more powerful members of the society. Research studies and positions taken by scholars and politicians tend to confirm the pre-existing belief, rather than dispassionately observe and evaluate the issue. Ultimately the panic dies out after several years or decades, but ultimately resurfaces when yet another new medium is introduced.
Criticisms of media violence research
Although organizations such as the American Academy of Pediatrics and the American Psychological Association have suggested that thousands (3500 according to the AAP) of studies have been conducted confirming this link, others have argued that this information is incorrect. Rather, only about two hundred studies (confirmed by meta-analyses such as Paik and Comstock, 1994) have been conducted in peer-reviewed scientific journals on television, movie, music and video game violence effects. Critics argue that about half find some link between media and subsequent aggression (but not violent crime), whereas the other half do not find a link between consuming violent media and subsequent aggression of any kind.
Criticisms of the media violence link focus on a number of methodological and theoretical problems including (but not limited to) the following (see Bryce & Kaye, 2011; Freedman, 2002; Olson, 2004; Tedeschi & Quigley, 1996; Pinker, 2002):
Failure to adequately control experimental conditions when assessing aggressive outcomes between violent and non-violent games (see Adachi & Willoughby, 2010). Traditionally, researchers have selected one violent game and one non-violent game, yet shown little consideration of the potentially different responses to these games as a result of differences in other game characteristics (e.g., level of action, frustration, enjoyment).
Failure to acknowledge the role of social contexts in which media violence is experienced. Within theoretical models explaining the influence of violent video game exposure on aggressive attitudes and behaviour, no acknowledgement is made towards understanding the influence of social gaming experiences and contexts on these outcomes. That is, differential outcomes of gaming arise as a result of different social contexts (online versus offline gaming) and social dynamics involved in social gaming experiences (Kaye & Bryce, 2012). Existing theoretical models assume that the outcomes of gaming are equivalent, regardless of these different contexts. This is a key limitation of current theory within media violence research
Failure to employ standardized, reliable and valid measures of aggression and media violence exposure. Although measurement of psychological variables is always tricky at best, it is generally accepted that measurement techniques should be standardized, reliable and valid, as demonstrated empirically. However, some scholars argue that the measurement tools involved are often unstandardized, sloppily employed and fail to report reliability coefficients. Examples include the "Competitive Reaction Time Test" in which participants believe that they are punishing an opponent for losing in a reaction time test by subjecting the opponent to noise blasts or electric shocks. There is no standardized way of employing this task, raising the possibility that authors may manipulate the results to support their conclusions. This task may produce dozens of different possible ways to measure "aggression", all from a single participant's data. Without a standardized way of employing and measuring aggression using this task, there is no way of knowing whether the results reported are a valid measure of aggression, or were selected from among the possible alternatives simply because they produced positive findings where other alternatives did not. Ferguson and Kilburn, in a paper in Journal of Pediatrics, have found that poorly standardized and validated measures of aggression tend to produce higher effects than well validated aggression measures.
Failure to report negative findings. Some scholars contend that many of the articles that purport positive findings regarding a link between media violence and subsequent aggression, on a closer read, actually have negative or inconclusive results. One example is the experimental portion of Anderson & Dill (2000; with video games) which measures aggression four separate ways (using an unstandardized, unreliable and unvalidated measure of aggression, the Competitive Reaction Time Test mentioned above) and finds significance for only one of those measures. Had a statistical adjustment known as a Bonferroni correction been properly employed, that fourth finding also would have been insignificant. This issue of selective reporting differs from the "file drawer" effect in which journals fail to publish articles with negative findings. Rather, this is due to authors finding a "mixed bag" of results and discussing only the supportive findings and ignoring the negative findings within a single manuscript. The problem of non-reporting of non-significant findings (the so-called "file cabinet effect") is a problem throughout all areas of science but may be a particular issue for publicized areas such as media violence.
Failure to account for "third" variables. Some scholars contend that media violence studies regularly fail to account for other variables such as genetics, personality and exposure to family violence that may explain both why some people become violent and why those same people may choose to expose themselves to violent media. Several recent studies have found that, when factors such as mental health, family environment and personality are controlled, no predictive relationship between either video games or television violence and youth violence remain (Ferguson, San Miguel & Hartley, 2009; Ybarra et al., 2008, Figure 2).
Failure to adequately define "aggression." Experimental measures of aggression have been questioned by critics (Mussen & Rutherford, 1961; Deselms & Altman, 2003). The main concern of critics has been the issue of the external validity of experimental measures of aggression. The validity of the concept of aggression itself, however, is rarely questioned. Highly detailed taxonomies of different forms of aggression do exist. Whether researchers agree on the particular terminology used to indicate the particular sub-types of aggression (i.e. relational versus social aggression), concepts of aggression are always operationally defined in peer-reviewed journals. However many of these operational definitions of aggression are specifically criticized. Many experimental measures of aggression are rather questionable (i.e. Mussen & Rutherford, 1961; Berkowitz, 1965; Bushman & Anderson, 2002; Deselms & Altman, 2003). Other studies fail to differentiate between "aggression" aimed at causing harm to another person, and "aggressive play" in which two individuals (usually children) may pretend to engage in aggressive behavior, but do so consensually for the purpose of mutual enjoyment. (Goldstein)
Small "effects" sizes. In the research world, the meaning of "statistical significance" can be ambiguous. A measure of effect size can aid in the interpretation of statistical significance. In a meta-analysis of 217 studies by Paik and Comstock (1994), effect sizes for experiments were r = .37 and r = .19 for surveys, which are small to moderate effects. Most of these studies however did not actually measure aggression against another person. Paik and Comstock note that when aggression toward another person, and particularly actual violent crime is considered, the relationship between media violence and these outcomes is near zero. Effects can vary according to their size (for example the effects of eating bananas on your mood could very well be "statistically significant" but would be tiny, almost imperceptible, whereas the effect of a death in the immediate family would also be "statistically significant" but obviously much larger). Media violence studies usually produce very small, transient effects that do not translate into large effects in the real world. Media violence researchers often defend this by stating that many medical studies also produce small effects (although as Block and Crain, 2007, note, these researchers may have miscalculated the effect sizes from medical research).
Media violence rates are not correlated with violent crime rates. One limitation of theories linking media violence to societal violence is that media violence (which appears to have been consistently and unfailingly on the rise since the 1950s) should be correlated with violent crime (which has been cycling up and down throughout human history). By discussing only the data from the 1950s through the 1990s, media violence researchers create the illusion that there is a correlation, when in fact there is not. Large spikes in violent crime in the United States occurred without associated media violence spikes during the 1880s (when records were first kept) and 1930s. The homicide rate in the United States has never been higher than during the 1930s. Similarly, this theory fails to explain why violent crime rates (including among juveniles) dramatically fell in the mid 1990s and have stayed low, during a time when media violence has continued to increase, and saw the addition of violent video games. Lastly media violence researchers can not explain why many countries with media violence rates similar to or equal to the U.S. (such as Norway, Canada, Japan, etc.) have much lower violent crime rates. Huesmann & Eron's own cross-national study (which is often cited in support of media violence effects) failed to find a link between television violence and aggressive behavior in most of the countries included in the analysis (including America, and even in studies on American boys).
Media violence on TV is a reflection of the level of violence that occurs in the real world. Many TV programmers argue that their shows just mirror the violence that goes on in the real world. Zev Braun,of CBS, in 1990 argued in a debate on the Violence Bill that, "We live in a violent society. Art imitates modes of life, not the other way around: it would be better for Congress to clean that society than to clean that reflection of society."
Response to criticisms
Social science uses randomized experiments to control for possible differences between media conditions, although these must be done with care. In a typical study, children or young adults are randomly assigned to different media conditions and then are observed when given an opportunity to be aggressive. Researchers who argue for causal effects have defended their work that is based on well-established methodological and statistical theory and on empirical data.
Regarding the inconclusive nature of some findings, media researchers who argue for causal effects often contend that it is the critics who are misinterpreting or selectively reporting studies (Anderson et al., 2003). It may be that both sides of the debate are highlighting separate findings that are most favorable to their own "cause".
Regarding "third" variables, media violence researchers who argue for causal effects acknowledge that other variables may play a role in aggression (Bushman & Anderson, 2001) and that aggression is due to a confluence of variables. These variables are known as "third variables" and if found, would probably be mediator variables (which differ from moderator variables). A mediator variable could 'explain away' media violence effects, whereas a moderator variable cannot. For instance, some scholars contend that trait aggressiveness has been demonstrated to moderate media violence effects (Bushman), although in some studies "trait aggression" does appear to account for any link between media violence exposure and aggression. Other variables have also been found to moderate media violence effects (Bushman & Geen, 1990). Another issue is the way in which experimental studies deal with potential confounding variables. Researchers use random assignment to attempt to neutralize the effects of what commonly are cited as third variables (i.e. gender, trait aggressiveness, preference for violent media). Because experimental designs employ random assignment to conditions, the effect of such attributive variables on experimental results is assumed to be random (not systematic). However, the same can not be said for correlational studies, and failure to control for such variables in correlational studies limits the interpretation of such studies. Often, something as simple as gender proves capable of "mediating" media violence effects.
Regarding aggression, the problem may have less to do with the definition of aggression, but rather how aggression is measured in studies, and how aggression and violent crime are used interchangeably in the public eye.
Much of the debate on this issue seems to revolve around ambiguity regarding what is considered a "small" effect. Media violence researchers who argue for causal effects contend that effect sizes noted in media violence effects are similar to those found in some medical research which is considered important by the medical community (Bushman & Anderson, 2001), although medical research may suffer from some of the same interpretational flaws as social science. This argument has been challenged as based on flawed statistics, however (Block & Crain, 2007). Block & Crain (2007) recently found that social scientists (Bushman & Anderson, 2001) had been miscalculating some medical effect sizes. The interpretation of effect size in both medical and social science remains in its infancy.
More recently, media violence researchers who argue for causal effects have acknowledged that societal media consumption and violent crime rates are not well associated, but claim that this is likely due to other variables that are poorly understood. However, this effect remains poorly explained by current media violence theories, and media violence researchers may need to be more careful not to retreat to an unfalsifiable theory – one that cannot be disproven (Freedman, 2002).
Researchers who argue for causal effects argue that the discrepancy of violent acts seen on TV compared to that in the real world are huge. One study looked at the frequency of crimes occurring in the real world compared with the frequency of crimes occurring in the following reality-based TV programs: America’s Most Wanted, Cops, Top Cops, FBI, The Untold Story and American Detective, (Oliver, 1994). The types of crimes were divided into two categories, violent crimes and non-violent crimes. 87% of crimes occurring in the real world are non-violent crimes, whereas only 13% of crimes occurring on TV are considered non-violent crimes. However, this discrepancy between media and real-life crimes may arguably dispute rather than support media effects theories. Some previous research linked boxing matches to homicies  although other researchers consider such linkages to be reminiscent of ecological fallacies (e.g. Freedman, 2002).
Media violence and youth violence
Several scholars (e.g. Freedman, 2002; Olson, 2004; Savage, 2004) have pointed out that as media content has increased in violence in the past few decades, violent crimes among youth have declined rapidly. Although most scholars caution that this decline cannot be attributed to a causal effect, they conclude that this observation argues against causal harmful effects for media violence. A recent long-term outcome study of youth found no long-term relationship between playing violent video games or watching violent television and youth violence or bullying.
Relationship between media violence and minor aggressive behaviors
Given that little evidence links media violence to serious physical aggression, bullying or youth violence, at present most of the debate appears to focus on whether media violence may have an impact on more minor forms of aggressiveness. At present, no consensus has been reached on this issue. For example in 1974 the US Surgeon General testified to congress that "the overwhelming consensus and the unanimous Scientific Advisory Committee’s report indicates that televised violence, indeed, does have an adverse effect on certain members of our society." However, by 2001, the US Surgeon General's office, The Department of Health and Human Services had largely reversed itself, relegating media violence to only a minor role and noting many serious limitations in the research. Studies, have also disagreed regarding whether media violence contributes to desensitization
^Anderson, C. A.; Berkowitz, L.; Donnerstein, E.; Huesmann, L. R.; Johnson, J. D.; Linz, D.; Malamuth, N. M.; Wartella, E. (2003). "The influence of media violence on youth". Psychological Science in the Public Interest4 (3): 81. doi:10.1111/j.1529-1006.2003.pspi_1433.x.edit
^Bushman, B.J., & Anderson, C.A. (2001). Media violence and the American public: Scientific facts versus media misinformation. American Psychologist, 56, 477-489.
^Bushman, B.J., & Green, R.G. (1990). Role of cognitive-emotional mediators and individual differences in the effects of media violence on aggression. Journal of Personality and Social Psychology, 58, 156-163.
^Block, J.J., & Crain, B.R. (2007). Omissions and errors in "Media Violence and the American Public." American Psychologist, 62, 252-253
^Phillips,D.P. (1986). Natural experiments on the effects of mass media violence on fatal aggression: Strengths and weaknesses of a new approach. In L. Berkowitz (Ed.), Advances in experimental social psychology (Vol.19,pp.207-250). Orlando,FL: Academic Press.
^ ab"Video Games and Youth Violence: A Prospective Analysis in Adolescents", Christopher J. Ferguson, Journal of Youth and Adolescence
^Ramos, Raul (2013). "Desensitization Comfortably numb or just yet another movie? Media violence exposure does not reduce viewer empathy for victims of real violence among primarily Hispanic viewers". Psychology of Popular Media Culture2: 2. doi:10.1037/a0030119.
Anderson, C. A. & Bushman, B. J. (2001) Media Violence and the American Public: Scientific Facts Versus Media Misinformation. American Psychologist
Bartholow, B. D.; Bushman, B. J.; Sestir, M. A. (2006). "Chronic violent video game exposure and desensitization to violence: Behavioral and event-related brain potential data". Journal of Experimental Social Psychology42 (4): 532. doi:10.1016/j.jesp.2005.08.006.edit
Berkowitz, L. (1965). "Some Aspects of Observed Aggression". Journal of personality and social psychology12 (3): 359–369. doi:10.1037/h0022221. PMID14333308. edit
Block, J. J.; Crain, B. R. (2007). "Omissions and errors in "Media violence and the American public."". American Psychologist62 (3): 252–253; discussion 253–4. doi:10.1037/0003-066X.62.3.252. PMID17469907. edit
Comstock, G. & Scharrer, E. (2003). Meta-analyzing the controversy over television violence and aggression. In D. Gentile (Ed.) Media Violence and Children, pp. 205–226. ISBN 978-0-275-97956-0
David-Ferdon C., Hertz MF Electronic Media and Youth Violence: A CDC Issue Brief for Researchers. Atlanta (GA): Centers for Disease Control; 2009. Retrieved from http://www.cdc.gov/violenceprevention /pdf/Electronic_Aggression_Researcher_Brief-a.pdf
Deselms, J. L.; Altman, J. D. (2003). "Immediate and Prolonged Effects of Videogame Violence". Journal of Applied Social Psychology33 (8): 1553. doi:10.1111/j.1559-1816.2003.tb01962.x.edit "This study examined the relationship between playing violent videogames and sensitivity to aggressive acts."
Elizabeth, J. E., & Morton, N. (2008). Exposure to media violence and young children with and without disabilities: Powerful opportunities for family-professional partnerships. Early Childhood Education Journal, 36(2), 105-112. doi: http://dx.doi.org/10.1007/s10643-008-0276-x
Ferguson, C. J. San Miguel, C., & Hartley, R. D. (2009). A multivariate analysis of youth violence and aggression: The influence of family, peers, depression and media violence. Journal of Pediatrics, 155(6), 904–908. Available at: http://www.tamiu.edu/~cferguson/LYOJPed.pdf
Huesmann, L.R, Moise, J.F., & Podolski, C.L. (1997). The effects of media violence on the development of antisocial behavior. In D. Stoff, J. Breiling & Master (Eds.) Handbook of Antisocial Behavior (pp. 181– 193). New York: John Wiley & SonsISBN 978-0-471-12452-8
Krcmar, M. & Kean, G. L., (2005). Uses and gratifications of media violence: Personality correlates of viewing and liking violent genre. Media Psychology, 7(4), 399-420.
The Lancet. (2008). Is exposure to media violence a public health risk? The Lancet, 371, 1137.
Larsson, H.; Andershed, H.; Lichtenstein, P. (2006). "A Genetic Factor Explains Most of the Variation in the Psychopathic Personality". Journal of Abnormal Psychology115 (2): 221–230. doi:10.1037/0021-843X.115.2.221. PMID16737387. edit
Mussen, P.; Rutherford, E. (1961). "Effects of aggressive cartoons on children's aggressive play". Journal of abnormal and social psychology62: 461–464. PMID13727111. edit
National Institute of Mental Health, Television and Behavior: Ten Years of Scientific Progress and Implications for the Eighties, 1982
Prinz, W. (1990). A common coding approach to perception and action. In O. Neumann and W. Prinz (Eds.) Relations between perception and action. Berlin: Springer.
Prinz, W. (2005). An Ideomotor Approach to Imitation. In Hurely, S. & N. Chater (Eds.) Perspectives on Imitation: From Neuroscience to Social Science (vol. 1). Cambridge, MA: MIT Press. ISBN 978-1-4237-5020-8
Slater, M. D. (2003). "Alienation, Aggression, and Sensation Seeking as Predictors of Adolescent Use of Violent Film, Computer, and Website Content". Journal of Communication53: 105. doi:10.1111/j.1460-2466.2003.tb03008.x.edit
Sparks, G.G., Sparks, E. A & Sparks, C.W. (2008) Media Violence. In J. Bryant (Ed),Media Effects: Advances in Theory and Research(3rd ed., pp. 269–286)
Weaver, A.J. (2011). A Meta-Analytical Review of Selective Exposure to and the Enjoyment of Media Violence. Journal of Broadcasting & Electronic Media, 55(2), 232-250.
Weaver A.J. & Wilson B.J. (2009). The role of graphic and sanitized violence in the enjoyment of television dramas. Human Communication Research, 35(3), 442-463.
Weaver A. & Kobach M.J. (2012), The Relationship Between Selective Exposure and the Enjoyment of Television Violence, Aggressive Behavior, Volume 38, 175–184.
Tedeschi, J. T.; Quigley, B. M. (1996). "Limitations of laboratory paradigms for studying aggression". Aggression and Violent Behavior1 (2): 163. doi:10.1016/1359-1789(95)00014-3.edit
Vidal, M. Á.; Clemente, M.; Espinosa, P. (2003). "Types of media violence and degree of acceptance in under-18s". Aggressive Behavior29 (5): 381. doi:10.1002/ab.10037.edit
Ybarra, M., Diener-West, M., Markow, D., Leaf, P., Hamburger, M., & Boxer, P. (2008). Linkages between internet and other media violence with seriously violent behavior by youth. Pediatrics, 122(5), 929–937.
Anderson, C. A., & Bushman, B. J. (2002). The effects of media violence on society. (Vol. 295, pp. 2377–2379). DOI: www.sciencemag.org