Frightening information and extraneous arousal: changing cognitions and behavior regarding nuclear war.

An experiment was designed to demonstrate that fear creates changes, that extraneous arousal modulates the effect of frightening information, and that Janis's (1967) theory may explain these effects. American students watched either a videotape depicting a nuclear attack or a nonfrightening videotape unrelated to nuclear war and were required to perform 10, 20, 35, or 100 jumping jacks. The results of the experiment demonstrated that fear was effective, especially at moderate levels of extraneous arousal, but high levels of arousal eliminated or reversed the effects.