Does violent screen media cause real-world aggression?

After more than six decades of research on screen violence and two decades focused on video games, the field remains genuinely divided. Laboratory studies find small short-term effects on aggressive thoughts and behavior, meta-analyses disagree over whether those effects are meaningful or artifacts of publication bias and weak measures, and long-term causal effects on real violence have not been demonstrated to the field's satisfaction; professional bodies have issued and then softened cautionary statements as the evidence has been re-examined.