PEDIATRICS Vol. 122 No. 5 November 2008, pp. 929-937 (doi:10.1542/peds.2007-3377)
ARTICLE |
Linkages Between Internet and Other Media Violence With Seriously Violent Behavior by Youth
a Internet Solutions for Kids, Santa Ana, California
b Departments of Biostatistics
d Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
c Harris Interactive, New York, New York
e Etiology and Surveillance Branch, Division of Violence Prevention, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Georgia
f Department of Psychology, Rutgers University, Newark, New Jersey
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ABSTRACT |
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OBJECTIVE. The goal was to examine the association between violence in the media and the expression of seriously violent behavior among older children and teenagers in a national sample.
METHODS. The Growing up with Media survey was a national, online survey of 1588 youths that was conducted in August and September 2006. Participants were 10- to 15-year-old youths who had used the Internet at least once in the past 6 months. The main outcome measure was self-reported seriously violent behavior, including (1) shooting or stabbing someone, (2) aggravated assault, (3) robbery, and (4) sexual assault.
RESULTS. Five percent of youths reported engaging in seriously violent behavior in the past 12 months. Thirty-eight percent reported exposure to violence online. Exposures to violence in the media, both online and off-line, were associated with significantly elevated odds for concurrently reporting seriously violent behavior. Compared with otherwise similar youths, those who indicated that many, most, or all of the Web sites they visited depicted real people engaged in violent behavior were significantly more likely to report seriously violent behavior. After adjustment for underlying differences in youth characteristics, respondents' alcohol use, propensity to respond to stimuli with anger, delinquent peers, parental monitoring, and exposures to violence in the community also were associated with significantly increased odds of concurrently reporting seriously violent behavior.
CONCLUSIONS. Exposure to violence in the media is associated with concurrent reports of seriously violent behavior across media (eg, games and music). Newer forms of violent media seem to be especially concerning.
Key Words: Internet • media • mental health • violence • youths
Abbreviations: OR—odds ratio • CI—confidence interval
Youth violence is a significant public health issue that negatively affects individuals, families, and communities.1,2 Estimates of combined direct and indirect costs associated with youth violence in the United States are more than $158 billion per year.2 In 2003, 15% of all arrests for violent crimes in the United States were of juveniles.3
Research on the development of aggression and violence indicates that seriously violent behavior occurs through a confluence of factors, including individual (eg, genetic factors), family (eg, poor parent-child relationships), school (poor academic performance), peer, and community (eg, neighborhood violence) characteristics.1,4 Although exposure to violence in the media is not the single reason for youth violence, it probably is, as the American Academy of Pediatrics asserts, "the single most easily remediable contributing factor."5 After an exhaustive review of available research, Anderson et al6 concluded that "the scientific debate over whether media violence increases aggression and violence is essentially over" and underscored the need for studies identifying the "magnitude of media-violence effects on the most severe types of violence."
With increased use of the Internet among young people,7,8 little is known about how exposure to violence online fits into our understanding of the effect of violent media. The Internet is fast becoming the telephone of the 21st century, with an estimated 97% of young people between the ages of 12 and 18 years using online communication.7 Almost all youths now have online access,7,8 and this access may increase opportunities for children and youths to be exposed to violence. Web sites such as "hate pages" that encourage discrimination against specific types of people and those reporting "real" violence, such as news Web sites, have the potential to reinforce cognitive styles and orientations that support aggressive responding, thereby increasing the perpetration of seriously violent behavior.6,9
Gaps remain in our understanding of the relationship between violence in the media and aggressive behavior, despite the prolific research activity that has taken place.4,6,9–20 First, despite substantial evidence of short-term effects of violence in the media on arousal, thoughts, and emotions,1,17–18 little research has considered the link with seriously violent or criminal behavior,1,16,18–20 particularly among youths. Second, effects of violence in the media on aggressive behavior seem to be particularly pronounced for younger children,21 and little research has considered the link for older children and adolescents.18 This study adds to the knowledge base on youth violence prevention by examining evidence of linkages between violence in the media and seriously violent behavior among adolescents. Analyses focus particularly on the prevalence and characteristics of youths exposed to violence online. The unique influence that violence in various media has on expression of seriously violent behavior in the context of other common risk factors for aggression and violence also is examined.
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METHODS |
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Data Source and Sampling Method
The Growing up with Media survey included 1588 youths 10 to 15 years of age. Data were collected in August and September 2006 and are used for the current analyses. The survey protocol was reviewed and approved by the Centers for Disease Control and Prevention institutional review board.
The sample was obtained from the Harris Poll Online opt-in panel, which includes >4 million members.22 Youth respondents were recruited through an initial e-mail contact with randomly identified, adult, Harris Poll Online members who had previously indicated that a child lived in the household. Households were enrolled by using a stratified random sample design based on youth age and gender. Harris Poll Online data are consistently comparable to data obtained from random telephone samples of the general populations, once propensity weighting and appropriate sample weights are applied.23–26 Propensity weighting is a well-established statistical technique that, when applied to data, minimizes the issue of nonrandomness and establishes equivalency for those who are in the sample versus those who are not because of self-selection bias.24,27,28 The response rate for this online survey was calculated as the number of individuals who started the survey divided by the number of e-mail invitations sent minus any e-mail invitations that were returned as undeliverable. The survey response rate (26%) is within the expected range for well-conducted online surveys.29,30
Data Collection Methods
Youth participants were required to be 10 to 15 years of age, to read English, and to have used the Internet in the past 6 months. This resulted in a broad range of Internet use and exposure, creating necessary exposure variability in the sample. After eligibility was confirmed and consent was obtained from the adults, the adults completed a 5-minute survey. They then passed the survey to the youths, who provided assent and completed the 21-minute survey. Youths were encouraged to return to the survey later if they were not in a separate space where their responses could be kept private from others (including their caregivers). Youths received a $10 gift certificate and caregivers $5 for their participation.
Measures
Seriously Violent Behavior
We operationalized seriously violent behavior as aggressive acts identified by the US Department of Justice as seriously violent,1,3,31,32 that is, (1) behavior likely to result in murder (ie, stabbing or shooting someone), (2) aggravated assault (ie, threatening someone with a weapon or attacking someone, resulting in the need for medical care), (3) robbery (ie, using a knife, a gun, or some other kind of weapon, such as a bat, to get something from someone else), or (4) sexual assault (kissing, touching, or doing anything sexual with another person when it was not wanted by that person). Approximately 5% of youths reported engaging in 
1 of the 4 types of seriously violent acts during the previous year (Cronbach's 
= .87), which is generally consistent with base rates observed in other large self-report surveys.33,34
Exposure to Violent Media
As in the Youth Internet Safety Survey,35 youths were asked whether they had viewed each of the following types of Web sites in the past 12 months: (1) a hate site (promoting hatred of a group of people because of who they are, how they look, or what they believe); (2) a Web site showing pictures of dead people or people dying, or a "snuff" site; (3) a Web site showing satanic rituals; (4) a Web site (including news-related sites) showing pictures of war, death, or "terrorism"; or (5) a Web site (not an online game) showing cartoons, such as stick people or animals, being beaten up, hurt, or killed. On the basis of focus group findings during the survey design stage, 2 different options for "no" responses were offered, that is, (1) "no, I don't know what this is" and (2) "no, I've heard of it but have never been to one."
Exposure to violence in other media was measured by asking youths to rate the amount of violence depicted in 5 different types of media (television, computer and video games, music, Web sites involving real people, and Web sites involving cartoons), using a similar question for each type, that is, "When you watch [media type], how many of them show physical fighting, hurting, shooting, or killing?"36 Response options were on a 4-point Likert scale, that is, 1 (almost none/none of them) to 4 (almost all/all of them).
Background Variables
Individual
Youths reported their race, ethnicity, and average per-day use of each of the Internet, games, television, and music. Caregivers reported the youths' gender and age. As an index of trait aggressiveness, the tendency to respond to stimuli with anger was measured with the 10-item State-Trait Anger Expression Inventory anger scale (Cronbach's = .85).37 Substance use was assessed with items based on those in the Youth Risk Behavior Survey,38 measuring use of 4 substances (alcohol, marijuana, inhalants, and "all other drugs").
Family
Caregivers reported demographic characteristics related to themselves and the household, including a felony conviction for any adult living in the household. Youths were asked questions about their relationship with the caregiver who knows the most about them by using items from the Youth Internet Safety Survey.35 Three domains were surveyed, namely, emotional bond with the caregiver (eg, "How well would you say you and this person get along?"), parental monitoring (eg, "Does this person know where you are when you are not at home?"), and coercive discipline (eg, "Does this person yell at you?"). Responses were captured on a 5-point Likert scale from 1 (never) to 5 (all of the time), expect for the first question (how well they got along), which was measured on a scale from 1 (very badly) to 4 (very well). Exposure to spousal abuse was queried of youths by using a modified question from the Juvenile Victimization Questionnaire, that is, "Ever, in real life, have you seen one of your parents get hit, slapped, punched, or beat up by your other parent, or their boyfriend or girlfriend?"39
School
Youths provided estimates of academic performance (ie, mostly A's to mostly D's and F's) and school behavior (number of detentions and suspensions in the past school year).
Peers
Youths indicated the number of close friends who had been arrested or "done things that could get them in trouble with the police."40
Community
Exposure to violence in the community was queried by using selected items from the Juvenile Victimization Questionnaire (eg, "Have you ever been in a place in real life where you could see or hear people being shot, bombs going off, or street riots?").39
Statistical Methods
Data were weighted statistically to reflect the population of adults with children 10 to 15 years of age in the United States, according to adult age, gender, race/ethnicity, region, education, and household income and child age and gender.41 Propensity score weighting was applied to adjust for adult respondents' propensity to be online.23–26 Valid (ie, not "refused" or "don't know") data were required for 80% of the variables examined. Three households were dropped as a result, leading to a final analytic sample size of 1585 households.
Our primary technique for quantifying associations was logistic regression analysis (Stata 9; Stata Corp, College Station, TX). Estimated associations between violence in the media and seriously violent behavior were reported first as unadjusted and then as adjusted for all background characteristics described above. As in the summary by Anderson et al,6 potential effect modifications of exposure to violent media by aggression level (ie, State-Trait Anger Expression Inventory results), youth age, and youth gender were each examined for inclusion in the final model.
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RESULTS |
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Study Group
Proportions and point estimates reported in text and tables were weighted as described above; numbers reported in tables are unweighted. As expected on the basis of the survey design, 48% of the youths were female and youths were an average of 13 years of age. Individual, family, school, peer, and community characteristics of the sample and how they differ according to the concurrent report of seriously violent behavior are shown in Table 1.
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Exposure to Violence Online
Thirty-eight percent of youths reported exposure to
1 type of violent Web site; 3% reported 3 different types of Web site exposures. The odds of reporting seriously violent behavior increased 50% (odds ratio [OR]: 1.50; 95% confidence interval [CI]: 1.13–1.98) with each increase in the number of different types of violent Web site exposures youths reported. Table 2 presents the frequency of exposure to violent Web sites.
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Associations Between Violence Online and Seriously Violent Behavior
The relative odds of seriously violent behavior with exposure to violence online are shown in Table 2. Six percent of youths who reported
1 type of exposure to violence online also reported seriously violent behavior, compared with 4% of youths who reported no exposure to violence online (design-based F1,1581 = 2.3; P = .13). With the exclusion of Web sites that showed pictures of death, war, and terrorism, 8% of youths who reported exposure to violence online (2% of all youths surveyed) also reported 1 seriously violent behavior, compared with 4% of youths who reported no exposure to violence online (3% of all youths surveyed; design-based F1,1581 = 7.2; P = .007).
Exposure to Violence Online in Comparison With Other Media
Forty-six percent of youths reported that many, most, or all of 1 type of media queried depicted violence. The odds of reporting seriously violent behavior increased 64% (OR: 1.64; 95% CI: 1.33–2.01) as the number of different types of media for which youths reported that many, most, or all exposures were violent increased by 1. Table 3 presents the frequency youth reports of violence consumed across the 5 types of media. Figure 1 depicts the associated relative odds of reporting seriously violent behavior.
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Unique Effects of Violence in the Media on Violent Behavior in the Context of Other Risk Factors
As shown in Fig 2, among otherwise similar youths, those who reported that many, most, or all of the Web sites they visited depicted real people fighting, shooting, or killing were 5 times (adjusted OR: 5.02; 95% CI: 2.03–12.43) more likely also to report seriously violent behavior, compared with those who reported that none of the Web sites they visited had these depictions. All other exposures to violent media were not significantly related to seriously violent behavior when underlying differences in individual, family, school, peer, and community characteristics were taken into account. Results were not modified significantly by the propensity to respond to stimuli with anger, youth age, or youth gender.
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DISCUSSION |
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Overall Findings
In this cross-sectional study of 10- to 15-year-old youths, exposure to violence in the media was associated with concurrent reports of seriously violent behaviors, including shooting or stabbing someone, aggravated assault, robbery, and sexual assault. This association was observed for violence depicted in music, in games, on television, and through the Internet. Our findings add to the growing evidence that violence in the media is related to aggressive behavior, including seriously violent behavior among youths. Reduction in youths' exposure to violent media should be viewed as an important aspect of violence prevention.
Influence of Internet Violence Within the Greater Context of Violent Media
Analyses of consumption of violent media indicated that use of violent media across types of media was linked to seriously violent behavior (Fig 1). When considered in the broader context of all other influential characteristics, Internet violence continued to be a significant predictor of seriously violent behavior (Fig 2). Indeed, with all other risk factors, including substance use, the proclivity to respond to stimuli with anger, having delinquent peers, poor parental monitoring, and being exposed to serious violence in the community, being held equal, reporting that many, most, or all of the Web sites visited depicted violence (ie, killing, fighting, and shooting) was associated with fivefold greater likelihood of also reporting seriously violent behavior, compared with reporting that none of the Web sites visited showed real people engaged in violence. Violence online may be particularly important to our understanding of seriously violent behavior among today's young people.
The disparity in effect size observed between the Internet and other violent media when all other underlying characteristics are taken into account is intriguing (Fig 2). The explanation for this finding is unknown and requires further investigation. Previous research suggested that more-interactive and more-realistic media are associated with stronger effects on aggressive behavior and attitudes.42–44 It is possible that exposures to real violence on the Internet are more immersive or interactive than any other type of violent exposure we examined. Cartoon violence, both in Web sites and in games, may be interactive but does not depict real people. Television violence may be realistic but not necessarily interactive. It is likely that the combination of the interactive environment commonly found online (eg, real-time chatting with peers who are simultaneously watching the same video) and the depiction of violence involving real people helps explain why exposure to Web sites depicting real people engaged in violence has the strongest association with seriously violent behavior. This and other emerging media that increase the interactivity with viewed exposures mimicking real life, such as the Nintendo Wii system (Nintendo, Kyoto, Japan), deserve additional research attention within this context.
Previous longitudinal research reported the direction of causality to be from exposure to violent media to greater aggressive behavior.16,45,46 The cross-sectional results of the current analyses raise an interesting question for future research, that is, are youths who visit violent Web sites more likely to manifest seriously violent behavior, are youths manifesting seriously violent behavior more likely to seek out violent Web sites, or, more probably, is the relationship bidirectional? It is important for longitudinal research to determine whether previous findings of effects of violent media translate to Internet-mediated violence. The current findings suggest that, as the number of different types of violent Web sites visited increases, the odds of concurrently reporting seriously violent behavior increases by 50%. Visiting specific types of violent Web sites, specifically hate sites and satanic sites, also is associated with elevated odds of seriously violent behavior. Although the temporality of events is unknown, targeted efforts aimed at preventing youths' exposures to violent Web sites seem warranted.
It should be noted that there were large proportions of youths who had never heard of these types of violent Web sites. Indeed, a lack of knowledge about violent Web sites might be protective against seriously violent behavior (Table 2). This might be reflective of a more-general naiveté that is protective against seriously violent behavior. Providers and parents face a challenge then; although the possibility of exposure to violence online needs to be acknowledged and efforts to reduce these exposures should be taken, adults should be sensitive to the possibility that a young person is unaware of violent Web sites. If youths make comments that suggest they have visited or heard about these Web sites, then adults should talk with them about their experiences and help them to interpret and to understand what they have seen, in order for them to place these exposures within the context of real-world or common-life experiences.21,47
Other Factors Contributing to Seriously Violent Behavior
As expected,1,16,46 many individual, family, school, peer, and community risk factors assessed were more commonly reported by youths who also reported seriously violent behavior, compared with those who did not (Table 1). Our findings suggest that, after adjustment for all other influential factors and consistent with considerable research in this area,48 community violence is linked to risk for seriously violent behavior in a manner similar to that associated with consumption of violent media. Unlike exposure to violence in the community, which often is out of the control of children and parents, exposure to violent Web sites is likely a purposeful behavior that adults have the ability to control. Health professionals should work to inform and to empower parents to take active steps in reducing the amount of violence to which youths are exposed online, including, for example, the installation of blocking and filtering software. Our findings underscore the consistent recommendation from youth violence researchers that preventions and interventions for youth violence should be multilevel and should address a wide range of deleterious social-contextual influences.49,50
Limitations and Future Directions
The most important issue affecting interpretation of the data is our cross-sectional design. This is a correlative study. Although associations can be identified, it cannot be determined which came first; perhaps violent exposures cause violent behavior, or perhaps youths who are violent are more attracted to violent exposures. The only mechanism to determine causality is through longitudinal experimental studies. In addition, there is literature suggesting that younger children (eg, 
7 years of age) may be particularly vulnerable to exposures to violent media.21 Seriously violent behavior detected in the current survey may be attributable to exposures to violent media years earlier in life. Furthermore, survey research such as this relies on self-reports. It is possible that youths underreported or overreported their exposures or behaviors. Efforts were taken to minimize this, including the use of computer-based versus face-to-face data collection and the reminder to youths that their information was private. The psychological impact of violent exposures online also was not queried. Possibly, in addition to associations with seriously violent behavior, associations with trauma symptoms would have been observed, as has been noted for exposure to television violence.51
Implications for Prevention
There is general agreement in the scientific community5,10–15 that viewing violence, at least for some children, "increases aggressive attitudes, values, and behaviors."52 The current survey suggests that this may be true for seriously violent behavior as well. We echo the call by Huesmann et al16 for a more-informed and more-critical policy debate about violence in the media. Furthermore, it is important to acknowledge the beneficial aspects of technology. Certainly youths use the Internet to express their individuality, to connect with friends and family members, and to access important health information.53–57 Still, the deleterious consequences of youth violence, coupled with the growing literature confirming relationships between violent behavior and violent media, demand a critical discussion of the issues and identification of realistic responses.
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ACKNOWLEDGMENTS |
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This work was supported by Cooperative Agreement U49/CE000206 from the Centers for Disease Control and Prevention. Its contents are solely the responsibility of the authors and do not necessarily reflect the official views of the CDC.
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FOOTNOTES |
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Accepted Feb 6, 2008.
Address correspondence to Michele L. Ybarra, MPH, PhD, Internet Solutions for Kids, 1820 East Garry Ave #105, Santa Ana, CA 92705. E-mail: michele{at}isolutions4kids.org
The contents of this article are solely the responsibility of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention.
The authors have indicated they have no financial relationships relevant to this article to disclose.
| What's Known on This Subject There is substantial evidence of short-term effects of violence in the media on arousal, thoughts, and emotions. Whether this relates to seriously violent behavior is not known.
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| What This Study Adds Exposure to violence in the media is significantly associated with reports of seriously violent behavior. Associations seem especially strong for youths who report that many, most, or all of the Web sites they visit depict real people engaged in physical violence.
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REFERENCES |
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TOPABSTRACTMETHODSRESULTSDISCUSSIONREFERENCES |
|---|
1. US Department of Health and Human Services. Risk Factors for Youth Violence. Youth Violence: A Report of the Surgeon General. Washington, DC: US Department of Health and Human Services, Office of the Surgeon General, SAMHSA; 2001
2. Centers for Disease Control and Prevention. Youth violence: fact sheet. Available at: www.cdc.gov/ncipc/factsheets/yvfacts.htm. Accessed April 23, 2007
3. Snyder HN, Sickmund M. Juvenile Offenders and Victims: 2006 National Report. Washington, DC: Department of Justice; 2006
4. Huesmann LR. The role of social information processing and cognitive schemas in the acquisition and maintenance of habitual aggressive behavior. In: Geen RG, Donnerstein E, eds. Human aggression: Theories, research, and implications for policy. New York: Academic Press; 1998;73–109
5. American Academy of Pediatrics, Committee on Communications. Media violence (policy statement RE9526).
Pediatrics. 1995;95
(6):949
–951
6. Anderson CA, Berkowitz L, Donnerstein E, et al. The influence of media violence on youth. Psychol Sci Public Interest. 2003;4 (3):81 –110[CrossRef]
7. University of California at Los Angeles, Center for Communication Policy. Surveying the Digital Future. Year 3. 2003. Los, Angeles, CA, University of California at Los Angeles. The UCLA Internet Report. Ref Type: Report
8. University of Southern California, Annenberg School Center for the Digital Future. Surveying the Digital Future: Ten years, ten trends. Year 4. 2004. Los Angeles, CA, University of Southern California. The Digital Future Report. Ref Type: Report
9. Huesmann LR. The role of social information processing and cognitive schemas in the acquisition and maintenance of habitual aggressive behavior. In: Geen RG, Donnerstein E, eds. Human Aggression: Theories, Research, and Implications for Policy. New York, NY: Academic Press; 1998:73–109
10. Funk JB. Video games. Adolesc Med. 1993;4 (3):589 –598[Medline]
11. Montgomery K. Youth and digital media: a policy research agenda. J Adolesc Health. 2000;27 (suppl 2):61 –68[CrossRef][Web of Science][Medline]
12. Cantor J. Media violence. J Adolesc Health. 2000;27 (suppl 2):30 –34[CrossRef][Web of Science][Medline]
13. Hogan M. Media matters for youth health. J Adolesc Health. 2000;27 (suppl 2):73 –76[Web of Science][Medline]
14. Rich M, Bar-on M. Child health in the information age: media education of pediatricians.
Pediatrics. 2001;107
(1):156
–162
15. Willis E, Strasburger V. Violence among children and adolescents: media violence. Pediatr Clin North Am. 1998;45 (2):319 –331[CrossRef][Web of Science][Medline]
16. Huesmann LR, Moise-Titus J, Podolski C, Eron LD. Longitudinal relations between children's exposure to TV violence and their aggressive and violent behavior in young adulthood: 1977–1992. Dev Psychol. 2003;39 (2):201 –221[CrossRef][Web of Science][Medline]
17. Bushman B, Huesmann LR. Effects of televised violence on aggression. In: Singer D, Singer J, eds. Handbook of Children and the Media. Thousand Oaks, CA: Sage; 2001:223–268
18. Browne KD, Hamilton-Giachritsis C. The influence of violent media on children and adolescents: a public-health approach. Lancet. 2005;365 (9460):702 –710[Web of Science][Medline]
19. Olson CK. Media violence research and youth violence data: why do they conflict?
Acad Psychiatry. 2004;28
(2):144
–150
20. Huesmann LR, Taylor LD. The role of media violence in violent behavior. Annu Rev Public Health. 2006;27 :393 –415[CrossRef][Web of Science][Medline]
21. Huesmann LR, Eron LD, Klein R, Brice P, Fischer P. Mitigating the imitation of aggressive behaviors by changing children's attitudes about media violence. J Pers Soc Psychol. 1983;44 (5):899 –910[CrossRef][Web of Science][Medline]
22. Harris Interactive. Online methodology. Available at: www.harrisinteractive.com/partner/methodology.asp. Accessed July 5, 2006
23. Berrens RP, Bohara AK, Jenkins-Smith H, Silva C, Weimer DL. The advent of Internet surveys for political research: a comparison of telephone and Internet samples. Polit Anal. 2003;11 (1):1 –22[Abstract]
24. Schonau M, Zapert K, Simon LP, et al. A comparison between response rates from a propensity-weighted Web survey and an identical RDD survey. Soc Sci Comput Rev. 2004;22 (1):128 –138[Abstract]
25. Taylor H, Bremer J, Overmeyer C, Siegel JW, Terhanian G. The record of Internet-based opinion polls in predicting the results of 72 races in the November 2000 US elections. Int J Market Res. 2001;43 :127 –136
26. Berrens RP, Bohara AK, Jenkins-Smith H, Silva C, Weimer DL. Information and effort in contingent valuation surveys: application to global climate change using national Internet samples. J Environ Econ Manage. 2004;47 (2):331 –363[CrossRef]
27. Rosenbaum PR, Rubin DB. Reducing bias in observational studies using subclassification on the propensity score. J Am Stat Assoc. 1984;79 (387):516 –524[CrossRef][Web of Science]
28. Terhanian G, Bremer J. Confronting the selection-bias and learning effects problems associated with Internet research. August 16, 2000. New York, NY, Harris Interactive. White Papers. Ref Type: Report
29. Cook C, Heath F, Thompson RL. A meta-analysis of response rates in Web- or Internet-based surveys. Educ Psychol Measure. 2000;60 (6):821 –836[CrossRef]
30. Kaplowitz MD, Hadlock TD, Levine R. A comparison of Web and mail survey response rates.
Public Opin Q. 2004;68
(1):94
–101
31. US Department of Justice. Crime in the United States, 1999. Washington, DC: Government Printing Office; 2000
32. Loeber R, Farrington DP, eds. Serious and Violent Juvenile Offenders: Risk Factors and Successful Interventions. Thousand Oaks, CA: Sage; 1998
33. Snyder HN, Espiritu RC, Huizinga D, Loeber R, Petechuk D. Prevalence and Development of Child Delinquency. Washington, DC: Department of Justice; 2003. Report NCJ 193411
34. Huizinga D, Loeber R, Thornberry TP. Recent Findings From the Program of Research on the Causes and Correlates of Delinquency. Washington, DC: Government Printing Office; 1995. Report NCJ 159042
35. Finkelhor D, Mitchell K, Wolak J. Online Victimization: A Report on the Nation's Youth. Alexandria, VA: National Center for Missing and Exploited Children; 2000
36. Windle M, Grunbaum JA, Elliott MN, et al. Healthy Passages: a multilevel, multimethod longitudinal study of adolescent health. Am J Prev Med. 2004;27 (2):164 –172[CrossRef][Web of Science][Medline]
37. Forgays DG, Forgays DK, Speilberger CD. Factor structure of the State-Trait Anger Expression Inventory. J Pers Assess. 1997;69 (3):497 –507[CrossRef][Web of Science][Medline]
38. Eaton DK, Kann L, Kinchen S, et al. Youth risk behavior surveillance: United States, 2005. MMWR Survill Summ. 2006;55 (SS05):1 –108
39. Finkelhor D, Hamby SL, Ormrod R, Turner H. The Juvenile Victimization Questionnaire: reliability, validity, and national norms. Child Abuse Negl. 2005;29 (4):383 –412[CrossRef][Web of Science][Medline]
40. Battin SR, Thornberry TP, Hawkins JD, and Krohn MD. Gang Membership, Delinquent Peers, and Delinquent Behavior: Seattle Social Development Project—Methods. NCJ 171119. 1998. Washington, DC, Office of Juvenile Justice and Delinquency Prevention, US Department of Justice. Juvenile Justice Bulletin. Available at: www.ojjdp.ncjrs.org/jjbulletin/9810_2/g2.html. Accessed March 9, 2008
41. Bureau of Labor Statistics, Bureau of the Census. Current population survey. Available at: www.bls.census.gov/cps/cpsmain.htm. Accessed July 5, 2006
42. Gentile D, Anderson CA. Violent video games: the newest media violence hazard. In: Gentile D, ed. Media Violence and Children. Westport, CT: Praeger; 2003:131–152
43. Anderson CA, Bushman B. Effects of violent video games on aggressive behavior, aggressive cognition, aggressive affect, physiological arousal, and prosocial behavior: a meta-analytic review of the scientific literature. Psychol Sci. 2001;12 (5):353 –359[CrossRef][Web of Science][Medline]
44. Anderson CA. Violent video games increase aggression and violence. Presented at the US Senate Commerce Committee Hearing on the Impact of Interactive Violence on Children, March 21, 2000. Available at: www.psychology.iastate.edu/faculty/caa/abstracts/2000-2004/00Senate.html. Accessed March 9, 2008
45. Eron LD, Huesmann LR, Lefkowitz MM, Walder LO. Does television violence cause aggression? Am Psychol. 1972;27 (4):253 –263[CrossRef][Medline]
46. Bushman B, Huesmann LR. Short-term and long-term effects of violent media on aggression in children and adults.
Arch Pediatr Adolesc Med. 2006;160
(4):348
–352
47. Nathanson AI. Identifying and explaining the relationship between parental mediation and children's aggression. Commun Res. 1999;26 (2):124 –143[CrossRef]
48. Guerra NG, Huesmann LR, Spindler A. Community violence exposure, social cognition, and aggression among urban elementary school children. Child Dev. 2003;74 (5):1561 –1576[CrossRef][Web of Science][Medline]
49. Boxer P, Dubow EF. A social-cognitive information-processing model for school-based aggression reduction and prevention programs: issues for research and practice. Appl Prev Psychol. 2001;10 (3):117 –192
50. Guerra NG, Boxer P, Kim T. A cognitive-ecological approach to serving students with emotional and behavioral disorders: application to aggressive behavior. Behav Disord. 2005;30 (3):277 –288
51. Villani S. Impact of media on children and adolescents: a 10-year review of the research. J Am Acad Child Adolesc Psychiatry. 2001;40 (4):392 –401[CrossRef][Web of Science][Medline]
52. Congressional Public Health Summit. Joint statement on the impact of entertainment violence on children. Available at: www.aap.org/advocacy/releases/jstmtevc.htm. Accessed January 15, 2001
53. Rideout V. Generation Rx.com: How young people use the Internet for health information. 20011211a. 12-11-2001. Menlo Park, CA, Henry J. Kaiser Family Foundation. Ref Type: Report Available at: www.kff.org/entmedia/20011211a-index.cfm. Accessed March 9, 2008
54. Ybarra M, Suman M. Reasons, assessments, and actions taken: sex and age differences in uses of Internet health information.
Health Educ Res. 2008;23
(3):512
–521
55. Roberts DF, Foehr UG, Rideout V. Generation M: Media in the Lives of 8–18 Year Olds. Menlo Park, CA: Henry J. Kaiser Family Foundation; 2005
56. Lenhart A, Madden M. Social Networking Websites and Teens: An Overview. Washington, DC: Pew Internet and American Life Project; 2007
57. Lenhart A, Madden M, Hitlin P. Teens and Technology: Youth Are Leading the Transition to a Fully Wired and Mobile Nation. Washington, DC: Pew Internet and American Life Project; 2005
PEDIATRICS (ISSN 1098-4275). ©2008 by the American Academy of Pediatrics
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