Abstract: | The current study assessed the effectiveness of two behavior manipulations created to differentially lower aggressive responses in a laboratory task. It was hypothesized that the reactive anger manipulation would have the greatest effect for reactive aggressive behavior and the instrumental manipulation would significantly affect proactive aggressive behavior and slightly affect the reactive behavior. Fifty participants played pinball in competition for points against an unknown peer, whose responses were actually controlled by the experimenter. Participants could push a noise button, sending the peer an annoying noise; a tilt button, interfering with the opponent's game; or a no answer button, offering a pro‐social alternative to aggression. After playing four rounds, participants were randomly assigned to either a reactive anger or a positive instrumental manipulation group; they then played pinball again for four rounds. Results indicate that the instrumental manipulation significantly lowered aggressive responses for both reactive and proactive behavior. The reactive manipulation effected aggressive responses only for use of the noise button and produced significantly lower levels of anger. Aggr. Behav. 29:215–227, 2003. © 2003 Wiley‐Liss, Inc. |