Addressing and Breaking the Link between Media Violence and Aggression in Adolescence: A Longitudinal Experimental Intervention Study

Monday, November 18, 2013

Barbara Krahé

Professor of Social Psychology
University of Potsdam, Germany

Attraction to violent media is high in adolescence, especially among males, and many studies have demonstrated a path from media violence use to aggressive behavior. However, there is a lack of experimental data addressing the long-term relations between media violence use and aggression, not least because assigning participants to a heavy diet of violent media over time is precluded by ethical concerns. Our research adopted an experimental approach that compared two groups of participants who were randomly assigned to an intervention designed to reduce media violence use or a non-intervention control group over a four-year period. This combined longitudinal-experimental approach facilitates the testing of causal hypotheses about the link between violent media use and aggression. Participants were 2,000 adolescents who were in 7th or 8th grade at the start of the study. A subgroup of n= 350 was assigned to a five-week class-based intervention between the first and the second data wave and were compared to a matched control group from the longitudinal sample. The efficacy of the intervention was examined at Wave 2, followed by two further assessments another 12 (Wave 3) and 24 (Wave 4) months later. At the post-intervention measurement, the intervention group reported significantly lower media violence use than did the control group, controlling for nonviolent media use and a range of demographic covariates. The intervention group also showed less normative acceptance of aggression and aggressive behavior, but these effects were limited to participants with higher baseline levels of aggression. Lower media violence use at Wave 2 predicted less physical aggression at Wave 3 for the total group and less normative acceptance of aggression among those participants who scored high on physical aggression at baseline. Effects of the intervention through lower media violence use at Wave 2 on reduced aggression and normative beliefs were still present at Wave 3, but were no longer significant at Wave 4. The findings have implications for understanding the role of violent media in the development of aggression in adolescence and for designing effective theory-based interventions.


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