Four hypotheses bearing on factors determining substitute behavior and degree of overt aggression have been deduced from the general laws of frustration and of learning, and evidence gathered from a questionnaire designed to permit standardized recall of real-life situations has been presented to substantiate them. Several generalizations may be made: The frequency of substitute responses varies positively with the strength of anticipatory responses to punishment-for-being-aggressive. The frequency of substitute responses varies inversely with the strength of instigation to the frustrated goal response. Overtness of aggression varies inversely with the amount of punishment anticipated as a consequence of such behavior. Overtness of aggression varies positively with the strength of instigation to the frustrated goal response. Overt aggression is more satisfying than non-overt aggression or substitute responses in the sample frustrating situations used in this study. (PsycINFO Database Record (c) 2006 APA, all rights reserved)