Thomas, M. H., & Tell, P. M. (1974). Effects of viewing real versus fantasy violence upon interpersonal aggression. Journal of Research in Personality, 8 (2), 153-160.

Abstract:  Of 96 male undergraduates, 32 Ss saw a violent film which they were told represented a real event, 32 saw the same film presented as a fictional event, and the remaining Ss saw no film. 16 Ss in each group had been attacked previously by a confederate while the others had not. Each S was then given an opportunity to aggress against the confederate by administering shocks to him as punishment in a learning task. Results indicate that Ss who observed real violence delivered stronger shocks to the confederate than Ss who viewed fantasy violence or saw no film. Ss who were angered and saw the real film were the most punitive toward the confederate. (PsycINFO Database Record (c) 2004 APA, all rights reserved)