ارتباط بین مواجهه با خشونت در رسانه ها خود گزارش شده و رتبه بندی معلمین از پرخاشگری و رفتار اجتماعی در میان نوجوانان آلمان

The relations between adolescents’ habitual usage of media violence and their tendency to engage in aggressive and prosocial behavior in a school setting were examined in a cross-sectional study with 1688 7th and 8th graders in Germany who completed measures of violent media exposure and normative acceptance of aggression. For each participant, ratings of prosocial and aggressive behavior were obtained from their class teacher. Media violence exposure was a unique predictor of teacher-rated aggression even when relevant covariates were considered, and it predicted prosocial behavior over and above gender. Path analyses confirmed a direct positive link from media violence usage to teacher-rated aggression for girls and boys, but no direct negative link to prosocial behavior was found. Indirect pathways were identified to higher aggressive and lower prosocial behavior via the acceptance of aggression as normative. Although there were significant gender differences in media violence exposure, aggression, and prosocial behavior, similar path models were identified for boys and girls.

In March 2009, Germany was shocked by a school massacre in which a 17-year-old killed nine students and three teachers at his former school, shooting three further people during his flight from police before turning his gun against himself. This terrible incident followed two earlier school shootings in 2002 and 2007 as well as a number of foiled attempts during the same period. In each of the three cases, there was no apparent motive but it was quickly proclaimed that the assailants had been avid users of media violence, harboring large collections of violent video games. Tragic events such as these have helped to place the question of a link between exposure to media violence and aggression squarely on the public agenda, in Germany and in other countries where outbursts of violent behavior by adolescents have been a sad reality. Although somewhat less controversial among aggression researchers, both the existence of such a link and its interpretation in terms of a causal relationship has been the object of intense debate within the wider scientific community (Huesmann & Taylor, 2003). Moreover, the issue of potentially harmful effects of habitual exposure to violent media has been expanded to consider not just the possibility of an increase in aggression but also a decrease in prosocial behavior (Bushman & Huesmann, 2006). Most studies available to date that examined the link between exposure to media violence and aggression were conducted in North America. However, even in the age of globalization, patterns of media violence usage and their cultural contexts may vary considerably, calling for a wider data base from different countries to examine the generalizability of results (e.g., Anderson et al., 2008 and Möller and Krahé, 2009). The present paper reports a cross-sectional study with a large sample of secondary school students in Germany, relating self-reports of media violence exposure to teacher ratings of aggressive and prosocial behavior as shown in a school setting. Meta-analytic evidence has consistently demonstrated substantial effect sizes for the link between exposure to violent media and the tendency to engage in aggression, across different methodologies (Anderson & Bushman, 2002), different media (Anderson, 2004 and Paik and Comstock, 1994), different settings (Christensen & Wong, 2007), and different outcome variables at the cognitive, affective, and behavioral level (Bushman & Huesmann, 2006). In addition, there is evidence of a negative relation between media violence exposure and readiness to engage in prosocial behavior (Anderson, 2004 and Bushman and Huesmann, 2006). With few exceptions (e.g., Anderson, Gentile, & Buckley, 2007, Study 1; Polman, de Castro, & van Aken, 2008), research with children and adolescents has been based on surveys and observational data rather than experimental designs because exposing children to media violence as an experimental manipulation is considered problematic. A recent study by Boxer, Huesmann, Bushman, O’Brien, and Moceri (2009) examined preference for violent media in conjunction with other known risk factors of aggression in two samples of high school students and incarcerated juvenile delinquents, using a combined index of self-reports as well as parent and teacher ratings of aggressive behavior. Preference for violent media had a predictive effect on aggressive behavior over and above the impact of other personal and social-contextual risk factors, such as psychopathology and exposure to neighborhood violence. Observational learning has been proposed as a central process underlying the link between media violence as an input variable and aggression as well as prosocial behavior as outcome variables. Observational learning refers to the acquisition of cognitive structures that promote specific behaviors from observing others perform those of similar behaviors. Watching media characters behave in a violent fashion can trigger a process of observational learning in which a new cognitive and behavioral repertoire is acquired. Bandura’s (1977) social learning theory argues that imitation is most likely to occur if the models are attractive and if they are rewarded for their behavior. Both these conditions are true for many forms of media violence. Content analyses of media violence depictions have shown that aggression is often performed by attractive and likeable characters whose actions are presented as legitimized by a good cause and who are rewarded by positive outcomes (e.g., National Television Violence Study, 1997). A conceptual framework specifying how repeated exposure to violence changes cognitions and behavior through social learning has been elaborated by Huesmann (Huesmann, 1998 and Huesmann and Kirwil, 2007). It is based on the assumption that social behavior in general, and aggressive behavior in particular, are controlled to a large extent by cognitive scripts that are used as guides for behavior and social problem-solving. A script consists of stored knowledge structures about how the person should behave in particular situations and what the likely outcome of those behaviors would be. Aggressive scripts are primed and retrieved when attributions about the current situation activate concepts connected to the script. Whether or not a script is utilized also depends on the passage of the script through a series of filters. The script must not seem incompatible with one’s normative beliefs about what behaviors are appropriate, and thinking about the outcome of the script must also make one “feel good”. To the extent that aggression is portrayed as acceptable, violent media contribute to the development of normative beliefs about aggression as a “normal” and appropriate form of behavior. Huesmann and Guerra (1997) found a positive relationship between aggression-enhancing normative beliefs and aggressive behavior in 1st and 4th graders in the domain of physical aggression. Krahé and Möller (2004) provided cross-sectional evidence of normative acceptance of aggression as a mediator between usage of violent video games and aggression, and a subsequent longitudinal study showed that violent video game usage predicted normative acceptance of aggression over a period of 30 months (Möller & Krahé, 2009). The promotion of aggressive scripts through habitual exposure to violent media depicting aggression as acceptable and successful also plays a key role in the General Aggression Model (GAM) by Anderson and Bushman (2001). In addition to the effects on aggressive behavior, habitual media violence is thought to reduce users’ willingness to engage in prosocial behavior. Meta-analyses confirmed this relation but found it to be somewhat weaker than the link obtained for aggression as an outcome variable (e.g., Bushman & Huesmann, 2006). In an observational study by Silvern and Williamson (1987), children aged 4 to 6 showed less prosocial behavior after watching a cartoon or playing a video game containing violent content compared to a baseline assessment. Wiegman and van Schie (1998) obtained peer ratings of prosocial behavior for a sample of 7th and 8th graders in the Netherlands. Adolescents showing a preference for violent media were rated as less prosocial by their classmates. Bushman and Anderson (2009) found that participants who had played a violent video game for 20 min took longer to intervene in support of a victim in a staged fight, and moviegoers about to watch a violent film took longer to help a woman on crutches than those about to watch a nonviolent film. To the extent that aggression is regarded as normal and acceptable, normative beliefs should also reduce the perceived need to help others. In violent media, aggressive behavior is seen as acceptable because it is not real and therefore victims do not really suffer, explaining negative links between media violence exposure and normative beliefs about aggression with moral reasoning (Funk, Buchman, Jenks, & Bechtoldt, 2003). Through the same principles of observational learning that can explain an increase in aggression, watching others’ failure to show support for victims of violence in media depictions may decrease viewers’ willingness to engage in prosocial behavior when encountering a person in need of help. Disregard for the suffering of others that is characteristic of many forms of media violence may thus serve to undermine the belief that people apparently in need of help should be offered support, weakening the development of prosocial scripts. Past research has found substantial gender differences in the preference for violent media contents, with males being far more attracted by and exposed to media violence than females (Kirsh, 2006). There is also evidence of greater male then female physical aggression (Archer, 2004 and Buss and Perry, 1992). This does not necessarily suggest that males and females also differ in their susceptibility to media violence in terms of enhancing aggression. Longitudinal studies reported similar relationships between media violence exposure and aggression for both genders (e.g., Huesmann, Moise-Titus, Podolski, & Eron, 2003). This finding is supported by meta-analytic studies yielding similar effect sizes of the media violence–aggression link for men and women (see Anderson et al., 2003). Thus, it appears that the covariation of media violence usage and aggression is not substantially affected by gender differences in usage. Many previous studies have used self-reports of aggression and prosocial behavior as outcome measures which may overestimate the link with self-reported media violence exposure due to shared method variance. In the present study, we relied on teacher reports of a student’s aggressive and prosocial behavior to obtain behavioral information from an independent source. A similar approach was used by Lösel, Bliesener, and Bender (2007) in a longitudinal study with 7th and 8th grade boys relating media violence consumption to teacher-rated aggression assessed 20 months later. A significant correlation was found between media violence exposure and physical aggression as rated by the teacher. In a study focusing on violent video games, Gentile and Gentile (2008) found a correlation of r = .29 between amount of playing violent video games and teacher-rated physical aggression in a sample of 3rd to 5th graders. Based on the theorizing and research outlined above, the present study examined the link between adolescents’ usage of media violence and their aggressive and prosocial behavior as rated by their teachers. Normative acceptance of aggression was included as a mediator in the relationship between media violence exposure and prosocial as well as aggressive behavior. In particular, we predicted that the higher the usage of violent media, the more aggressive and the less prosocial behavior participants would show as perceived by their class teachers (Hypothesis 1). Secondly, we proposed that the link between media violence exposure and aggression as well as prosocial behavior would be mediated at least partly by the increased acceptance of aggression as normative (Hypothesis 2). Regarding the role of gender, we proposed that despite expected differences in media violence exposure, aggression and prosocial behavior as well as in the normative acceptance of aggression included as a mediator variable, the processes that underlie the effects of media violence would be similar in boys and girls. Therefore, we predicted that the specified links of media violence exposure with aggression and prosocial behavior would hold for both boys and girls.