REVIOUS research by Weiss and Fine (14) has indicated that subjects evidencing high aggressiveness, as measured by the TAT and the Rosenzweig P-F Study, were influenced more by a communication designed to provoke punitive opinions than were those evidencing low fantasy aggressiveness. This rinding supported the data of earlier correlational research which related personality variables to opinions at one time, but not to changes in opinions (1,2). The general research hypothesis for the authors' previous study presented a compound independent variable involving aggressiveness and exposure to a communication. Only the latter aspect was experimentally controlled. The theoretical advantage of verifying an hypothesis by complete experimental methodology was the primary motive for the present research. While personality factors, such as aggressiveness, can not readily be influenced, temporary states analogous to them can be induced. This was the method adopted for the current investigation.The broad theoretical statement underlying the research asserts that communication effectiveness is facilitated when congruency exists between response predispositions of the communicatees and the communication appeals. To elaborate this interactive relationship, the effect of a communication designed to induce lenient opinions on a topic should be examined. The prediction would then be that high aggressives would be less influenced by such a communication than would low aggressives. The verification of this prediction was the second purpose of the current research. It was also considered advisable in view of the assumption of congruency to attempt the development of an ego-satisfying experience, so that aggression arousal may be contrasted with ego satisfaction rather than simply no aggression arousal. As a minimum, this second type of induction should aid the production 1 The research reported in this article was done under Contract , between Boston University and the Office of Naval Research. of two clearly separable groups along the dimension of aggressiveness.