Hapkiewicz, W. G., & Stone, R. D. (1974). The effect of realistic versus imaginary aggressive models on children’s interpersonal play. Child Study Journal, 4 (2), 47-58.

Abstract:  Randomly assigned 180 6-10 yr olds in elementary school to same-sex pairs, and randomly assigned each pair to 1 of 3 treatment groups: real-life aggressive film, aggressive cartoon, or nonaggressive film. Results reveal a Treatment * Sex interaction effect indicating ordered males who viewed planned realistic aggressive film were significantly more aggressive in play than males who viewed the other films (p < .05). There was no significant difference between the aggressive cartoon and nonaggressive film groups. Males were generally more aggressive than females, while females exhibited significantly more prosocial (sharing) behavior than males (p < .01). (PsycINFO Database Record (c) 2004 APA, all rights reserved)